Sample records for tcp performance enhancement

  1. Performance Analysis of TCP Enhancements in Satellite Data Networks

    NASA Technical Reports Server (NTRS)

    Broyles, Ren H.

    1999-01-01

    This research examines two proposed enhancements to the well-known Transport Control Protocol (TCP) in the presence of noisy communication links. The Multiple Pipes protocol is an application-level adaptation of the standard TCP protocol, where several TCP links cooperate to transfer data. The Space Communication Protocol Standard - Transport Protocol (SCPS-TP) modifies TCP to optimize performance in a satellite environment. While SCPS-TP has inherent advantages that allow it to deliver data more rapidly than Multiple Pipes, the protocol, when optimized for operation in a high-error environment, is not compatible with legacy TCP systems, and requires changes to the TCP specification. This investigation determines the level of improvement offered by SCPS-TP's Corruption Mode, which will help determine if migration to the protocol is appropriate in different environments. As the percentage of corrupted packets approaches 5 %, Multiple Pipes can take over five times longer than SCPS-TP to deliver data. At high error rates, SCPS-TP's advantage is primarily caused by Multiple Pipes' use of congestion control algorithms. The lack of congestion control, however, limits the systems in which SCPS-TP can be effectively used.

  2. Study and Simulation of Enhancements for TCP Performance Over Noisy High Latency Links

    NASA Technical Reports Server (NTRS)

    Partridge, Craig

    1999-01-01

    The goal of this study is to better understand how TCP behaves over noisy, high-latency links such as satellite links and propose improvements to TCP implementations such that TCP might better handle such links. This report is comprised of a series of smaller reports, presentations and recommendations. Included in these documents are a summary of the TCP enhancement techniques for large windows, protect against wrap around (PAWS), use of selective acknowledgements (SACK), increasing TCP's initial window and recommendations to implement TCP pacing.

  3. SCPS-TP: A Satellite-Enhanced TCP

    NASA Technical Reports Server (NTRS)

    Scott, Keith; Torgerson, Leigh

    2004-01-01

    This viewgraph presentation reviews the Space Communications Protocol Standard Transport Protocol (SCPS-TP) which is a satellite enhanced Transport Control Protocol (TCP). The contents include: 1) Purpose; 2) Background; 3) Stressed Communication Environments; 4) SCPS-TP Features; 5) SCPS-TP Performance; 6) Performance Enhancing Proxies (PEPs); and 7) Ongoing and Future SCPS-TP Work.

  4. TCP Performance Enhancement Over Iridium

    NASA Technical Reports Server (NTRS)

    Torgerson, Leigh; Hutcherson, Joseph; McKelvey, James

    2007-01-01

    In support of iNET maturation, NASA-JPL has collaborated with NASA-Dryden to develop, test and demonstrate an over-the-horizon vehicle-to-ground networking capability, using Iridium as the vehicle-to-ground communications link for relaying critical vehicle telemetry. To ensure reliability concerns are met, the Space Communications Protocol Standards (SCPS) transport protocol was investigated for its performance characteristics in this environment. In particular, the SCPS-TP software performance was compared to that of the standard Transmission Control Protocol (TCP) over the Internet Protocol (IP). This paper will report on the results of this work.

  5. Potential performance bottleneck in Linux TCP

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wu, Wenji; Crawford, Matt; /Fermilab

    2006-12-01

    TCP is the most widely used transport protocol on the Internet today. Over the years, especially recently, due to requirements of high bandwidth transmission, various approaches have been proposed to improve TCP performance. The Linux 2.6 kernel is now preemptible. It can be interrupted mid-task, making the system more responsive and interactive. However, we have noticed that Linux kernel preemption can interact badly with the performance of the networking subsystem. In this paper we investigate the performance bottleneck in Linux TCP. We systematically describe the trip of a TCP packet from its ingress into a Linux network end system tomore » its final delivery to the application; we study the performance bottleneck in Linux TCP through mathematical modeling and practical experiments; finally we propose and test one possible solution to resolve this performance bottleneck in Linux TCP.« less

  6. Performance of TCP variants over LTE network

    NASA Astrophysics Data System (ADS)

    Nor, Shahrudin Awang; Maulana, Ade Novia

    2016-08-01

    One of the implementation of a wireless network is based on mobile broadband technology Long Term Evolution (LTE). LTE offers a variety of advantages, especially in terms of access speed, capacity, architectural simplicity and ease of implementation, as well as the breadth of choice of the type of user equipment (UE) that can establish the access. The majority of the Internet connections in the world happen using the TCP (Transmission Control Protocol) due to the TCP's reliability in transmitting packets in the network. TCP reliability lies in the ability to control the congestion. TCP was originally designed for wired media, but LTE connected through a wireless medium that is not stable in comparison to wired media. A wide variety of TCP has been made to produce a better performance than its predecessor. In this study, we simulate the performance provided by the TCP NewReno and TCP Vegas based on simulation using network simulator version 2 (ns2). The TCP performance is analyzed in terms of throughput, packet loss and end-to-end delay. In comparing the performance of TCP NewReno and TCP Vegas, the simulation result shows that the throughput of TCP NewReno is slightly higher than TCP Vegas, while TCP Vegas gives significantly better end-to-end delay and packet loss. The analysis of throughput, packet loss and end-to-end delay are made to evaluate the simulation.

  7. Performance Evaluation of FAST TCP Traffic-Flows in Multihomed MANETs

    NASA Astrophysics Data System (ADS)

    Mudassir, Mumajjed Ul; Akram, Adeel

    In Mobile Ad hoc Networks (MANETs) an efficient communication protocol is required at the transport layer. Mobile nodes moving around will have temporary and rather short-lived connectivity with each other and the Internet, thus requiring efficient utilization of network resources. Moreover the problems arising due to high mobility, collision and congestion must also be considered. Multihoming allows higher reliability and enhancement of network throughput. FAST TCP is a new promising transport layer protocol developed for high-speed high-latency networks. In this paper, we have analyzed the performance of FAST TCP traffic flows in multihomed MANETs and compared it with standard TCP (TCP Reno) traffic flows in non-multihomed MANETs.

  8. Improving TCP Network Performance by Detecting and Reacting to Packet Reordering

    NASA Technical Reports Server (NTRS)

    Kruse, Hans; Ostermann, Shawn; Allman, Mark

    2003-01-01

    There are many factors governing the performance of TCP-basec applications traversing satellite channels. The end-to-end performance of TCP is known to be degraded by the reordering, delay, noise and asymmetry inherent in geosynchronous systems. This result has been largely based on experiments that evaluate the performance of TCP in single flow tests. While single flow tests are useful for deriving information on the theoretical behavior of TCP and allow for easy diagnosis of problems they do not represent a broad range of realistic situations and therefore cannot be used to authoritatively comment on performance issues. The experiments discussed in this report test TCP s performance in a more dynamic environment with competing traffic flows from hundreds of TCP connections running simultaneously across the satellite channel. Another aspect we investigate is TCP's reaction to bit errors on satellite channels. TCP interprets loss as a sign of network congestion. This causes TCP to reduce its transmission rate leading to reduced performance when loss is due to corruption. We allowed the bit error rate on our satellite channel to vary widely and tested the performance of TCP as a function of these bit error rates. Our results show that the average performance of TCP on satellite channels is good even under conditions of loss as high as bit error rates of 10(exp -5)

  9. Study and Simulation of Enhancements for TCP (Transmission Control Protocol) Performance Over Noisy, High-Latency Links

    NASA Technical Reports Server (NTRS)

    Shepard, Timothy J.; Partridge, Craig; Coulter, Robert

    1997-01-01

    The designers of the TCP/IP protocol suite explicitly included support of satellites in their design goals. The goal of the Internet Project was to design a protocol which could be layered over different networking technologies to allow them to be concatenated into an internet. The results of this project included two protocols, IP and TCP. IP is the protocol used by all elements in the network and it defines the standard packet format for IP datagrams. TCP is the end-to-end transport protocol commonly used between end systems on the Internet to derive a reliable bi-directional byte-pipe service from the underlying unreliable IP datagram service. Satellite links are explicitly mentioned in Vint Cerf's 2-page article which appeared in 1980 in CCR [2] to introduce the specifications for IP and TCP. In the past fifteen years, TCP has been demonstrated to work over many differing networking technologies, including over paths including satellites links. So if satellite links were in the minds of the designers from the beginning, what is the problem? The problem is that the performance of TCP has in some cases been disappointing. A goal of the authors of the original specification of TCP was to specify only enough behavior to ensure interoperability. The specification left a number of important decisions, in particular how much data is to be sent when, to the implementor. This was deliberately' done. By leaving performance-related decisions to the implementor, this would allow the protocol TCP to be tuned and adapted to different networks and situations in the future without the need to revise the specification of the protocol, or break interoperability. Interoperability would continue while future implementations would be allowed flexibility to adapt to needs which could not be anticipated at the time of the original protocol design.

  10. Quick Vegas: Improving Performance of TCP Vegas for High Bandwidth-Delay Product Networks

    NASA Astrophysics Data System (ADS)

    Chan, Yi-Cheng; Lin, Chia-Liang; Ho, Cheng-Yuan

    An important issue in designing a TCP congestion control algorithm is that it should allow the protocol to quickly adjust the end-to-end communication rate to the bandwidth on the bottleneck link. However, the TCP congestion control may function poorly in high bandwidth-delay product networks because of its slow response with large congestion windows. In this paper, we propose an enhanced version of TCP Vegas called Quick Vegas, in which we present an efficient congestion window control algorithm for a TCP source. Our algorithm improves the slow-start and congestion avoidance techniques of original Vegas. Simulation results show that Quick Vegas significantly improves the performance of connections as well as remaining fair when the bandwidth-delay product increases.

  11. On the Performance of TCP Spoofing in Satellite Networks

    NASA Technical Reports Server (NTRS)

    Ishac, Joseph; Allman, Mark

    2001-01-01

    In this paper, we analyze the performance of Transmission Control Protocol (TCP) in a network that consists of both satellite and terrestrial components. One method, proposed by outside research, to improve the performance of data transfers over satellites is to use a performance enhancing proxy often dubbed 'spoofing.' Spoofing involves the transparent splitting of a TCP connection between the source and destination by some entity within the network path. In order to analyze the impact of spoofing, we constructed a simulation suite based around the network simulator ns-2. The simulation reflects a host with a satellite connection to the Internet and allows the option to spoof connections just prior to the satellite. The methodology used in our simulation allows us to analyze spoofing over a large range of file sizes and under various congested conditions, while prior work on this topic has primarily focused on bulk transfers with no congestion. As a result of these simulations, we find that the performance of spoofing is dependent upon a number of conditions.

  12. Improving TCP Performance over Mobile Satellite Channels: The ACKPrime Approach

    NASA Technical Reports Server (NTRS)

    Scott, Keith; Czetty, Stephen

    1998-01-01

    Various issues associated with "Improving TCP Performance over Mobile Satellite Channels: The ACKPrime Approach" are presented in viewgraph form. Specific topics include: 1) TCP over mobile satellite links; 2) ways of breaking the control loop at the groundstation; 3) ACK implementation; and 4) ACK performance.

  13. Evolutionary Telemetry and Command Processor (TCP) architecture

    NASA Technical Reports Server (NTRS)

    Schneider, John R.

    1992-01-01

    A low cost, modular, high performance, and compact Telemetry and Command Processor (TCP) is being built as the foundation of command and data handling subsystems for the next generation of satellites. The TCP product line will support command and telemetry requirements for small to large spacecraft and from low to high rate data transmission. It is compatible with the latest TDRSS, STDN and SGLS transponders and provides CCSDS protocol communications in addition to standard TDM formats. Its high performance computer provides computing resources for hosted flight software. Layered and modular software provides common services using standardized interfaces to applications thereby enhancing software re-use, transportability, and interoperability. The TCP architecture is based on existing standards, distributed networking, distributed and open system computing, and packet technology. The first TCP application is planned for the 94 SDIO SPAS 3 mission. The architecture enhances rapid tailoring of functions thereby reducing costs and schedules developed for individual spacecraft missions.

  14. Novel β-TCP Coated Titanium Nanofiber Surface for Enhanced Bone Growth.

    PubMed

    Lim, Hyun-Pil; Park, Sang-Won; Yun, Kwi-Dug; Park, Chan; Ji, Min-Kyung; Oh, Gye-Jeong; Lee, Jong-Tak; Lee, Kwangmin

    2018-02-01

    In this study, we examined the effect of β-tricalcium phosphate (β-TCP) coating on alkali-treated CP Grade II titanium surface via RF magnetron sputtering on osteoblast like cell (MC3T3-E1) viability and bone formation in rat tibia. The specimens were divided into three groups; commercially pure titanium (control group), alkali-treated titanium with nanofiber structure (NF group) and β-TCP coating on alkali-treated titanium with nanofiber structure (TNF group). The surface characteristics of specimens were observed under a field emission scanning electron microscope (FE-SEM), and contact angle was measured. The cell viability was assessed in vitro after 1 day, 3 days and 7 days. Implants of 2.0 mm diameter and 5.0 mm length were inserted into the tibia of rats. After 4 wks, the histomorphometric analysis was performed. Group NF and group TNF showed improved hydrophilicity of Ti. Group TNF showed significantly higher cell viability (P < 0.05) after 7 days. The bone to implant contact (BIC) ratio of the control group, NF group, and TNF group were 32.3%, 35.5%, and 63.9%, respectively. The study results suggested that β-TCP coated alkali-treated titanium surface via RF magnetron sputtering might be effective in implant dentistry due to enhanced hydrophilicity, improved cell response, and better osseointegration.

  15. Impact of window decrement rate on TCP performance in an adhoc network

    NASA Astrophysics Data System (ADS)

    Suherman; Hutasuhut, Arief T. W.; Badra, Khaldun; Al-Akaidi, Marwan

    2017-09-01

    Transmission control protocol (TCP) is a reliable transport protocol handling end to end connection in TCP/IP stack. It works well in copper or optical fibre link, but experiences increasing delay in wireless network. Further, TCP experiences multiple retransmissions due to higher collision probability within wireless network. The situation may get worsen in an ad hoc network. This paper examines the impact half window or window reduction rate to the overall TCP performances. The evaluation using NS-2 simulator shows that the smaller the window decrement rate results the smaller end to end delay. Delay is reduced to 17.05% in average when window decrement rate decreases. Average jitter also decreases 4.15%, while packet loss is not affected.

  16. Analysis of the role of Arabidopsis class I TCP genes AtTCP7, AtTCP8, AtTCP22, and AtTCP23 in leaf development

    PubMed Central

    Aguilar-Martínez, José A.; Sinha, Neelima

    2013-01-01

    TCP family of plant-specific transcription factors regulates plant form through control of cell proliferation and differentiation. This gene family is comprised of two groups, class I and class II. While the role of class II TCP genes in plant development is well known, data about the function of some class I TCP genes is lacking. We studied a group of phylogenetically related class I TCP genes: AtTCP7, AtTCP8, AtTCP22, and AtTCP23. The similar expression pattern in young growing leaves found for this group suggests similarity in gene function. Gene redundancy is characteristic in this group, as also seen in the class II TCP genes. We generated a pentuple mutant tcp8 tcp15 tcp21 tcp22 tcp23 and show that loss of function of these genes results in changes in leaf developmental traits. We also determined that these factors are able to mutually interact in a yeast two-hybrid assay and regulate the expression of KNOX1 genes. To circumvent the issue of genetic redundancy, dominant negative forms with SRDX repressor domain were used. Analysis of transgenic plants expressing AtTCP7-SRDX and AtTCP23-SRDX indicate a role of these factors in the control of cell proliferation. PMID:24137171

  17. Analysis of the role of Arabidopsis class I TCP genes AtTCP7, AtTCP8, AtTCP22, and AtTCP23 in leaf development.

    PubMed

    Aguilar-Martínez, José A; Sinha, Neelima

    2013-01-01

    TCP family of plant-specific transcription factors regulates plant form through control of cell proliferation and differentiation. This gene family is comprised of two groups, class I and class II. While the role of class II TCP genes in plant development is well known, data about the function of some class I TCP genes is lacking. We studied a group of phylogenetically related class I TCP genes: AtTCP7, AtTCP8, AtTCP22, and AtTCP23. The similar expression pattern in young growing leaves found for this group suggests similarity in gene function. Gene redundancy is characteristic in this group, as also seen in the class II TCP genes. We generated a pentuple mutant tcp8 tcp15 tcp21 tcp22 tcp23 and show that loss of function of these genes results in changes in leaf developmental traits. We also determined that these factors are able to mutually interact in a yeast two-hybrid assay and regulate the expression of KNOX1 genes. To circumvent the issue of genetic redundancy, dominant negative forms with SRDX repressor domain were used. Analysis of transgenic plants expressing AtTCP7-SRDX and AtTCP23-SRDX indicate a role of these factors in the control of cell proliferation.

  18. ATM QoS Experiments Using TCP Applications: Performance of TCP/IP Over ATM in a Variety of Errored Links

    NASA Technical Reports Server (NTRS)

    Frantz, Brian D.; Ivancic, William D.

    2001-01-01

    Asynchronous Transfer Mode (ATM) Quality of Service (QoS) experiments using the Transmission Control Protocol/Internet Protocol (TCP/IP) were performed for various link delays. The link delay was set to emulate a Wide Area Network (WAN) and a Satellite Link. The purpose of these experiments was to evaluate the ATM QoS requirements for applications that utilize advance TCP/IP protocols implemented with large windows and Selective ACKnowledgements (SACK). The effects of cell error, cell loss, and random bit errors on throughput were reported. The detailed test plan and test results are presented herein.

  19. Strategy for Developing Expert-System-Based Internet Protocols (TCP/IP)

    NASA Technical Reports Server (NTRS)

    Ivancic, William D.

    1997-01-01

    The Satellite Networks and Architectures Branch of NASA's Lewis Research is addressing the issue of seamless interoperability of satellite networks with terrestrial networks. One of the major issues is improving reliable transmission protocols such as TCP over long latency and error-prone links. Many tuning parameters are available to enhance the performance of TCP including segment size, timers and window sizes. There are also numerous congestion avoidance algorithms such as slow start, selective retransmission and selective acknowledgment that are utilized to improve performance. This paper provides a strategy to characterize the performance of TCP relative to various parameter settings in a variety of network environments (i.e. LAN, WAN, wireless, satellite, and IP over ATM). This information can then be utilized to develop expert-system-based Internet protocols.

  20. A Simulation Study of Paced TCP

    NASA Technical Reports Server (NTRS)

    Kulik, Joanna; Coulter, Robert; Rockwell, Dennis; Partridge, Craig

    2000-01-01

    In this paper, we study the performance of paced TCP, a modified version of TCP designed especially for high delay- bandwidth networks. In typical networks, TCP optimizes its send-rate by transmitting increasingly large bursts, or windows, of packets, one burst per round-trip time, until it reaches a maximum window-size, which corresponds to the full capacity of the network. In a network with a high delay-bandwidth product, however, Transmission Control Protocol's (TCPs) maximum window-size may be larger than the queue size of the intermediate routers, and routers will begin to drop packets as soon as the windows become too large for the router queues. The TCP sender then concludes that the bottleneck capacity of the network has been reached, and it limits its send-rate accordingly. Partridge proposed paced TCP as a means of solving the problem of queueing bottlenecks. A sender using paced TCP would release packets in multiple, small bursts during a round-trip time in which ordinary TCP would release a single, large burst of packets. This approach allows the sender to increase its send-rate to the maximum window size without encountering queueing bottlenecks. This paper describes the performance of paced TCP in a simulated network and discusses implementation details that can affect the performance of paced TCP.

  1. High-Speed TCP Testing

    NASA Technical Reports Server (NTRS)

    Brooks, David E.; Gassman, Holly; Beering, Dave R.; Welch, Arun; Hoder, Douglas J.; Ivancic, William D.

    1999-01-01

    Transmission Control Protocol (TCP) is the underlying protocol used within the Internet for reliable information transfer. As such, there is great interest to have all implementations of TCP efficiently interoperate. This is particularly important for links exhibiting long bandwidth-delay products. The tools exist to perform TCP analysis at low rates and low delays. However, for extremely high-rate and lone-delay links such as 622 Mbps over geosynchronous satellites, new tools and testing techniques are required. This paper describes the tools and techniques used to analyze and debug various TCP implementations over high-speed, long-delay links.

  2. An Evaluation of TCP with Larger Initial Windows

    NASA Technical Reports Server (NTRS)

    Allman, Mark; Hayes, Christopher; Ostermann, Shawn

    1998-01-01

    Transmission Control Protocol (TCP's) slow start algorithm gradually increases the amount of data a sender injects into the network, which prevents the sender from overwhelming the network with an inappropriately large burst of traffic. However, the slow start algorithm can make poor use of the available band-width for transfers which are small compared to the bandwidth-delay product of the link, such as file transfers up to few thousand characters over satellite links or even transfers of several hundred bytes over local area networks. This paper evaluates a proposed performance enhancement that raises the initial window used by TCP from 1 MSS-sized segment to roughly 4 KB. The paper evaluates the impact of using larger initial windows on TCP transfers over both the shared Internet and dialup modem links.

  3. Known TCP Implementation Problems

    NASA Technical Reports Server (NTRS)

    Paxson, Vern (Editor); Allman, Mark; Dawson, Scott; Fenner, William; Griner, Jim; Heavens, Ian; Lahey, K.; Semke, J.; Volz, B.

    1999-01-01

    This memo catalogs a number of known TCP implementation problems. The goal in doing so is to improve conditions in the existing Internet by enhancing the quality of current TCP/IP implementations. It is hoped that both performance and correctness issues can be resolved by making implementors aware of the problems and their solutions. In the long term, it is hoped that this will provide a reduction in unnecessary traffic on the network, the rate of connection failures due to protocol errors, and load on network servers due to time spent processing both unsuccessful connections and retransmitted data. This will help to ensure the stability of the global Internet. Each problem is defined as follows: Name of Problem The name associated with the problem. In this memo, the name is given as a subsection heading. Classification one or more problem categories for which the problem is classified: "congestion control", "performance", "reliability", "resource management". Description A definition of the problem, succinct but including necessary background material. Significance A brief summary of the sorts of environments for which the problem is significant.

  4. Performance analysis of TCP traffic and its influence on ONU's energy saving in energy efficient TDM-PON

    NASA Astrophysics Data System (ADS)

    Alaelddin, Fuad Yousif Mohammed; Newaz, S. H. Shah; Lee, Joohyung; Uddin, Mohammad Rakib; Lee, Gyu Myoung; Choi, Jun Kyun

    2015-12-01

    The majority of the traffic over the Internet is TCP based, which is very sensitive to packet loss and delay. Existing research efforts in TDM-Passive Optical Networks (TDM-PONs) mostly evaluate energy saving and traffic delay performances under different energy saving solutions. However, to the best of our knowledge, how energy saving mechanisms could affect TCP traffic performance in TDM-PONs has hardly been studied. In this paper, by means of our state-of-art OPNET Modular based TDM-PON simulator, we evaluate TCP traffic delay, throughput, and Optical Network Unit (ONU) energy consumption performances in a TDM-PON where energy saving mechanisms are employed in ONUs. Here, we study the performances under commonly used energy saving mechanisms defined in standards for TDM-PONs: cyclic sleep and doze mode. In cyclic sleep mode, we evaluate the performances under two well-known sleep interval length deciding algorithms (i.e. fixed sleep interval (FSI) and exponential sleep interval deciding (ESID)) that an OLT uses to decide sleep interval lengths for an ONU. Findings in this paper put forward the strong relationship among TCP traffic delay, throughput and ONU energy consumption under different sleep interval lengths. Moreover, we reveal that under high TCP traffic, both FSI and ESID will end up showing similar delay, energy and throughput performance. Our findings also show that doze mode can offer better TCP throughput and delay performance at the price of consuming more energy than cyclic sleep mode. In addition, our results provide a glimpse on understanding at what point doze mode becomes futile in improving energy saving of an ONU under TCP traffic. Furthermore, in this paper, we highlight important research issues that should be studied in future research to maximize energy saving in TDM-PONs while meeting traffic Quality of Service requirements.

  5. On the Effective Evaluation of TCP

    NASA Technical Reports Server (NTRS)

    Allman, Mark; Falk, Aaron

    2000-01-01

    Understanding the performance of the Internet's Transmission Control Protocol (TCP) is important because it is the dominant protocol used in the Internet today. Various testing methods exist to evaluate TCP performance, however all have pitfalls an that need to be understood prior to obtaining useful results. Simulating TCP is difficult because of the wide range of variables, environments, and implementations available. Testing TCP modifications in the global Internet may not be the answer either: testing new protocols on real networks endangers other people's traffic and, if not done correctly, may also yield inaccurate or misleading results. In order for TCP research to be independently evaluated in the Internet research community there is a set of questions that researchers should try to answer. This paper attempts to list some of those questions and make recommendations as to how TCP testing can be structured to be provide useful answers.

  6. TCP Packet Trace Analysis. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Shepard, Timothy J.

    1991-01-01

    Examination of a trace of packets collected from the network is often the only method available for diagnosing protocol performance problems in computer networks. This thesis explores the use of packet traces to diagnose performance problems of the transport protocol TCP. Unfortunately, manual examination of these traces can be so tedious that effective analysis is not possible. The primary contribution of this thesis is a graphical method of displaying the packet trace which greatly reduce, the tediousness of examining a packet trace. The graphical method is demonstrated by the examination of some packet traces of typical TCP connections. The performance of two different implementations of TCP sending data across a particular network path is compared. Traces many thousands of packets long are used to demonstrate how effectively the graphical method simplifies examination of long complicated traces. In the comparison of the two TCP implementations, the burstiness of the TCP transmitter appeared to be related to the achieved throughput. A method of quantifying this burstiness is presented and its possible relevance to understanding the performance of TCP is discussed.

  7. Fabrication and characterization of a biodegradable Mg-2Zn-0.5Ca/1β-TCP composite.

    PubMed

    Huang, Yan; Liu, Debao; Anguilano, Lorna; You, Chen; Chen, Minfang

    2015-09-01

    A biodegradable magnesium matrix and beta-tricalcium phosphate (β-TCP) particles reinforced composite Mg-2Zn-0.5Ca/1beta-TCP (wt.%) was fabricated for biomedical applications by the novel route of combined high shear solidification (HSS) and equal channel angular extrusion (ECAE). The as-cast composite obtained by HSS showed a fine and equiaxed grain structure with globally uniformly distributed β-TCP particles in aggregates of 2-25 μm in size. The ECAE processing at 300 °C resulted in further microstructural refinement and the improvement of β-TCP particle distribution. During ECAE, the β-TCP aggregates were broken into smaller ones or individual particles, forming a dispersion in the matrix. Such fabricated composite exhibited enhanced hardness and in vitro corrosion resistance. The enhanced hardness was attributed to both the addition of β-TCP particles and grain refinement while the development of a Ca-P rich surface layer from β-TCP during corrosion was responsible for the improvement in corrosion resistance. The composite was characterized in terms of microstructural evolution during fabrication, mechanical properties and electrochemical performance during polarization and immersion tests in a simulated body fluid. Discussions are made on the benefits of both HSS and ECAE and the mechanisms responsible for the enhanced corrosion resistance. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Fabrication and characterization of toughness-enhanced scaffolds comprising β-TCP/POC using the freeform fabrication system with micro-droplet jetting.

    PubMed

    Gao, Li; Li, Cuidi; Chen, Fangping; Liu, Changsheng

    2015-06-24

    A novel elastomeric material, poly(1,8-octanediol-co-citrate) (POC), has demonstrated tremendous versatility because of its advantageous toughness, tunable degradation properties, and efficient drug release capability. In this study, POC was used to improve the mechanical performance of β-tricalcium phosphate (β-Ca3(PO4)2, β-TCP). (3D) β-TCP/POC composite scaffolds were fabricated by a 3D printing technique based on the freeform fabrication system with micro-droplet jetting (FFS-MDJ). The physiochemical properties, compressive modulus, drug release behavior, and cell response of β-TCP/POC composite scaffolds were systematically investigated. The results showed that β-TCP/POC scaffolds had uniform macropores of 300-400 μm, porosity of approximately 45%, biodegradability in phosphate-buffered saline, and high compressive modulus of 50-75 MPa. With the incorporation of POC into β-TCP, the toughness of the composite scaffolds was improved significantly. Moreover, β-TCP/POC scaffolds exhibited sustained drug (ibuprofen (IBU)) release capability. Additionally, β-TCP/POC scaffolds facilitated C2C12 cell attachment and proliferation. It was indicated that the 3D-printed porous β-TCP/POC scaffolds with high compressive modulus and good drug delivery performance might be a promising candidate for bone defect repair.

  9. GbTCP, a cotton TCP transcription factor, confers fibre elongation and root hair development by a complex regulating system.

    PubMed

    Hao, Juan; Tu, Lili; Hu, Haiyan; Tan, Jiafu; Deng, Fenglin; Tang, Wenxin; Nie, Yichun; Zhang, Xianlong

    2012-10-01

    As the most important natural raw material for textile industry, cotton fibres are an excellent model for studying single-cell development. Although expression profiling and functional genomics have provided some data, the mechanism of fibre development is still not well known. A class I TCP transcription factor (designated GbTCP), encoding 344 amino acids, was isolated from the normalized cDNA library of sea-island cotton fibre (from -2 to 25 days post anthesis). GbTCP was preferentially expressed in the elongating cotton fibre from 5 to 15 days post anthesis. Some expression was also observed in stems, apical buds, and petals. RNAi silencing of GbTCP produced shorter fibre, a reduced lint percentage, and a lower fibre quality than the wild-type plants. Overexpression of GbTCP enhanced root hair initiation and elongation in Arabidopsis and regulated branching. Solexa sequencing and Affymetrix GeneChip analysis indicated that GbTCP positively regulates the level of jasmonic acid (JA) and, as a result, activates downstream genes (reactive oxygen species, calcium signalling, ethylene biosynthesis and response, and several NAC and WRKY transcription factors) necessary for elongation of fibres and root hairs. JA content analysis in cotton also confirmed that GbTCP has a profound effect on JA biosynthesis. In vitro ovule culture showed that an appropriate concentration of JA promoted fibre elongation. The results suggest that GbTCP is an important transcription factor for fibre and root hair development by regulating JA biosynthesis and response and other pathways, including reactive oxygen species, calcium channel and ethylene signalling.

  10. GbTCP, a cotton TCP transcription factor, confers fibre elongation and root hair development by a complex regulating system

    PubMed Central

    Zhang, Xianlong

    2012-01-01

    As the most important natural raw material for textile industry, cotton fibres are an excellent model for studying single-cell development. Although expression profiling and functional genomics have provided some data, the mechanism of fibre development is still not well known. A class I TCP transcription factor (designated GbTCP), encoding 344 amino acids, was isolated from the normalized cDNA library of sea-island cotton fibre (from –2 to 25 days post anthesis). GbTCP was preferentially expressed in the elongating cotton fibre from 5 to 15 days post anthesis. Some expression was also observed in stems, apical buds, and petals. RNAi silencing of GbTCP produced shorter fibre, a reduced lint percentage, and a lower fibre quality than the wild-type plants. Overexpression of GbTCP enhanced root hair initiation and elongation in Arabidopsis and regulated branching. Solexa sequencing and Affymetrix GeneChip analysis indicated that GbTCP positively regulates the level of jasmonic acid (JA) and, as a result, activates downstream genes (reactive oxygen species, calcium signalling, ethylene biosynthesis and response, and several NAC and WRKY transcription factors) necessary for elongation of fibres and root hairs. JA content analysis in cotton also confirmed that GbTCP has a profound effect on JA biosynthesis. In vitro ovule culture showed that an appropriate concentration of JA promoted fibre elongation. The results suggest that GbTCP is an important transcription factor for fibre and root hair development by regulating JA biosynthesis and response and other pathways, including reactive oxygen species, calcium channel and ethylene signalling. PMID:23105133

  11. A simulation-based study of HighSpeed TCP and its deployment

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Souza, Evandro de

    2003-05-01

    The current congestion control mechanism used in TCP has difficulty reaching full utilization on high speed links, particularly on wide-area connections. For example, the packet drop rate needed to fill a Gigabit pipe using the present TCP protocol is below the currently achievable fiber optic error rates. HighSpeed TCP was recently proposed as a modification of TCP's congestion control mechanism to allow it to achieve reasonable performance in high speed wide-area links. In this research, simulation results showing the performance of HighSpeed TCP and the impact of its use on the present implementation of TCP are presented. Network conditions includingmore » different degrees of congestion, different levels of loss rate, different degrees of bursty traffic and two distinct router queue management policies were simulated. The performance and fairness of HighSpeed TCP were compared to the existing TCP and solutions for bulk-data transfer using parallel streams.« less

  12. Cell cycle dependent intracellular distribution of two spliced isoforms of TCP/ILF3 proteins.

    PubMed

    Xu, You Hai; Leonova, Tatyana; Grabowski, Gregory A

    2003-12-01

    TCP80 is an approximately 80kDa mammalian cytoplasmic protein that binds to a set of mRNAs and inhibits their translation in vitro and ex vivo. This protein has high sequence similarity to interleukin-2 enhancer-binding factors (NF90/ILF3) and the M-phase phosphoprotein (MPP4)/DRBP76. A 110kDa immunologic isoform of TCP80/NF90/MPP4/DRBP76, termed TCP110, also is present in cytoplasm and nuclei of many types of cells. A cDNA sequence coding for TCP110 was derived by 5(')RACE. The TCP110 sequence is identical to ILF3. The gene coding for TCP110/ILF3 mapped to human chromosome 19 and the gene organization was analyzed using TCP80 and TCP110/ILF3 cDNA sequences. The TCP/ILF3 gene spans >34.8kb and contains 21 exons. At least one alternatively spliced product involving exons 19-21 exists and predicts the formation of either TCP80 or TCP110/ILF3. However, the functional relationships of TCP80 and TCP110/ILF3 required elucidation. The metabolic turnover rates and subcellular distribution of TCP80 and TCP110/ILF3 during the cell cycle showed TCP80 to be relatively stable (t(1/2)=5 days) in the cytoplasmic compartment. In comparison, TCP110/ILF3 migrated between the cytoplasmic and nuclear compartments during the cell cycle. The TCP110 C-terminal segment contains an additional nuclear localizing signal that plays a role in its nuclear translocation. This study indicates that the multiple cellular functions, i.e., translation control, interleukin-2 enhancer binding, or cell division, of TCP/ILF3 are fulfilled by alternatively spliced isoforms.

  13. Enhanced bone formation in the vicinity of porous β-TCP scaffolds exhibiting slow release of collagen-derived tripeptides.

    PubMed

    Kamikura, Keita; Minatoya, Tsutomu; Terada-Nakaishi, Michiko; Yamamoto, Shoko; Sakai, Yasuo; Furusawa, Toshitake; Matsushima, Yuta; Unuma, Hidero

    2017-09-01

    It has been experimentally proven that orally ingested collagen-derived tripeptides (Ctp) are quickly absorbed in the body and effectively promote the regeneration of connective tissues including bone and skin. Ctp are capable to activate osteoblasts and fibroblasts, which eventually promotes tissue regeneration. Based on these findings, a hypothesis was formulated in this study that direct delivery of Ctp to bone defect would also facilitate tissue regeneration as well as oral administration. To test the hypothesis, we prepared a bone augmentation material with the ability to slowly release Ctp, and investigated its in vivo bone regeneration efficacy. The implant material was porous β-tricalcium phosphate (β-TCP) scaffold which was coated with a co-precipitated layer of bone-like hydroxyapatite and Ctp. The β-TCP was impregnated with approximately 0.8%(w/w) Ctp. Then, the Ctp-modified β-TCP was implanted into bone defects of Wistar rats to evaluate in vivo efficacy of Ctp directly delivered from the material to the bone defects. The control was pristine porous β-TCP. In vitro tests showed that Ctp were steadily released from the co-precipitated layer for approximately two weeks. The Ctp-modified scaffolds significantly promoted new bone formation in vivo in their vicinity as compared with pristine β-TCP scaffolds; 6 weeks after the implantation, Ctp-modified scaffolds promoted twice as much bone formation as the control implants. Consequently, we achieved the slow and steady release of Ctp, and found that direct delivery of Ctp from implant materials was effective for bone regeneration as well as oral administration. A β-TCP scaffold capable of slowly releasing bone-enhancing substances significantly promoted bone formation.

  14. Flow-oriented dynamic assembly algorithm in TCP over OBS networks

    NASA Astrophysics Data System (ADS)

    Peng, Shuping; Li, Zhengbin; He, Yongqi; Xu, Anshi

    2008-11-01

    OBS is envisioned as a promising infrastructure for the next generation optical network, and TCP is likely to be the dominant transport protocol in the next generation network. Therefore, it is necessary to evaluate the performance of TCP over OBS networks. The assembly at the ingress edge nodes will impact the network performance. There have been several Fixed Assembly Period (FAP) algorithms proposed. However, the assembly period in FAP is fixed, and it can not be adjusted according to the network condition. Moreover, in FAP, the packets from different TCP sources are assembled into one burst. In that case, if such a burst is dropped, the TCP windows of the corresponding sources will shrink and the throughput will be reduced. In this paper, we introduced a flow-oriented Dynamic Assembly Period (DAP) algorithm for TCP over OBS networks. Through comparing the previous and current burst lengths, DAP can track the variation of TCP window, and update the assembly period dynamically for the next assembly. The performance of DAP is evaluated over a single TCP connection and multiple connections, respectively. The simulation results show that DAP performs better than FAP at almost the whole range of burst dropping probability.

  15. UV photolysis for enhanced phenol biodegradation in the presence of 2,4,6-trichlorophenol (TCP).

    PubMed

    Song, Jiaxiu; Wang, Wenbing; Li, Rongjie; Zhu, Jun; Zhang, Yongming; Liu, Rui; Rittmann, Bruce E

    2016-02-01

    A bacterial strain isolated from activated sludge and identified as Bacillus amyloliquefaciens could biodegrade phenol, but 2,4,6-trichlorophenol (TCP) inhibited phenol biodegradation and biomass growth. UV photolysis converted TCP into dichlorocatechol, monochlorophenol, and dichlorophenol, and this relieved inhibition by TCP. Phenol-removal and biomass-growth rates were significantly accelerated after UV photolysis: the monod maximum specific growth rate (μ(max)) increased by 9% after TCP photolysis, and the half-maximum-rate concentration (K(S)) decreased by 36%. Thus, the major benefit of UV photolysis in this case was to transform TCP into a set of much-less-inhibitory products.

  16. Adsorption of 1,2,3-Trichloropropane (TCP) to meet a MCL of 5 ppt.

    PubMed

    Babcock, Roger W; Harada, Bryce K; Lamichhane, Krishna M; Tsubota, Korey T

    2018-02-01

    1,2,3-Trichloropropane (TCP) is a groundwater contaminant in the drinking water aquifers in Hawaii and some other states. Granular activated carbon (GAC) has been used for 30 years to treat approximately 60 million gallons per day of TCP-contaminated groundwater in Hawaii. The State of Hawaii's current maximum contaminant level (MCL) for TCP is 600 ng/L (ppt), and consideration is being given to lower the MCL to 5 ppt. There is no EPA MCL for TCP. A study was conducted to determine if any GAC could meet a 5 ppt MCL for TCP, and if so, how many bedvolumes (BVs) could be treated prior to breakthrough. Constant Diffusivity-Rapid Small-Scale Column Tests (CD-RSSCTs) were performed to evaluate GAC adsorption of TCP. Three different groundwaters and six different GACs were utilized. The RSSCTs with the currently-utilized GAC were predictive of the performance of the GAC contactors (50,000 BVs to breakthrough). Any of the six GACs could meet a MCL of 5 ppt and some could do so for 150,000 or more BVs. No single GAC was optimal for all three well sites, indicating effects of subtle undefined differences in the water matrix and/or GAC physiochemical properties. The coal-based direct-activated carbon currently being used is the least optimal for all three well sites with respect to meeting a potential new TCP MCL of 5 ppt. The most effective GACs for Kunia were the Calgon coal-based GAC and the Siemens enhanced coconut shell GAC, while the most effective for Waipahu were the Siemens regular and enhanced coconut shell GACs, and the most effective for Mililani was the Calgon coal-based GAC. Choosing just one GAC for use at all three well sites (rather than the optimal for each site) would result in a reduction of treatment run time of 1 year at one well site (63% reduction). Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. TCP Pacing Developed

    NASA Technical Reports Server (NTRS)

    Ivancic, William D.

    2002-01-01

    Transmission control protocol (TCP) was conceived and designed to run over a variety of communication links, including wireless and high-bandwidth links. However, with recent technological advances in satellite and fiber-optic networks, researchers are reevaluating the flexibility of TCP. The TCP pacing and packet pair probing implementation may help overcome two of the major obstacles identified for efficient bandwidth utilization over communication links with large delay-bandwidth products.

  18. Analysis of functional redundancies within the Arabidopsis TCP transcription factor family.

    PubMed

    Danisman, Selahattin; van Dijk, Aalt D J; Bimbo, Andrea; van der Wal, Froukje; Hennig, Lars; de Folter, Stefan; Angenent, Gerco C; Immink, Richard G H

    2013-12-01

    Analyses of the functions of TEOSINTE-LIKE1, CYCLOIDEA, and PROLIFERATING CELL FACTOR1 (TCP) transcription factors have been hampered by functional redundancy between its individual members. In general, putative functionally redundant genes are predicted based on sequence similarity and confirmed by genetic analysis. In the TCP family, however, identification is impeded by relatively low overall sequence similarity. In a search for functionally redundant TCP pairs that control Arabidopsis leaf development, this work performed an integrative bioinformatics analysis, combining protein sequence similarities, gene expression data, and results of pair-wise protein-protein interaction studies for the 24 members of the Arabidopsis TCP transcription factor family. For this, the work completed any lacking gene expression and protein-protein interaction data experimentally and then performed a comprehensive prediction of potential functional redundant TCP pairs. Subsequently, redundant functions could be confirmed for selected predicted TCP pairs by genetic and molecular analyses. It is demonstrated that the previously uncharacterized class I TCP19 gene plays a role in the control of leaf senescence in a redundant fashion with TCP20. Altogether, this work shows the power of combining classical genetic and molecular approaches with bioinformatics predictions to unravel functional redundancies in the TCP transcription factor family.

  19. Analysis of functional redundancies within the Arabidopsis TCP transcription factor family

    PubMed Central

    Danisman, Selahattin; de Folter, Stefan; Immink, Richard G. H.

    2013-01-01

    Analyses of the functions of TEOSINTE-LIKE1, CYCLOIDEA, and PROLIFERATING CELL FACTOR1 (TCP) transcription factors have been hampered by functional redundancy between its individual members. In general, putative functionally redundant genes are predicted based on sequence similarity and confirmed by genetic analysis. In the TCP family, however, identification is impeded by relatively low overall sequence similarity. In a search for functionally redundant TCP pairs that control Arabidopsis leaf development, this work performed an integrative bioinformatics analysis, combining protein sequence similarities, gene expression data, and results of pair-wise protein–protein interaction studies for the 24 members of the Arabidopsis TCP transcription factor family. For this, the work completed any lacking gene expression and protein–protein interaction data experimentally and then performed a comprehensive prediction of potential functional redundant TCP pairs. Subsequently, redundant functions could be confirmed for selected predicted TCP pairs by genetic and molecular analyses. It is demonstrated that the previously uncharacterized class I TCP19 gene plays a role in the control of leaf senescence in a redundant fashion with TCP20. Altogether, this work shows the power of combining classical genetic and molecular approaches with bioinformatics predictions to unravel functional redundancies in the TCP transcription factor family. PMID:24129704

  20. Genome-wide identification and expression analysis of TCP transcription factors in Gossypium raimondii.

    PubMed

    Ma, Jun; Wang, Qinglian; Sun, Runrun; Xie, Fuliang; Jones, Don C; Zhang, Baohong

    2014-10-16

    Plant-specific TEOSINTE-BRANCHED1/CYCLOIDEA/PCF (TCP) transcription factors play versatile functions in multiple aspects of plant growth and development. However, no systematical study has been performed in cotton. In this study, we performed for the first time the genome-wide identification and expression analysis of the TCP transcription factor family in Gossypium raimondii. A total of 38 non-redundant cotton TCP encoding genes were identified. The TCP transcription factors were divided into eleven subgroups based on phylogenetic analysis. Most TCP genes within the same subfamily demonstrated similar exon and intron organization and the motif structures were highly conserved among the subfamilies. Additionally, the chromosomal distribution pattern revealed that TCP genes were unevenly distributed across 11 out of the 13 chromosomes; segmental duplication is a predominant duplication event for TCP genes and the major contributor to the expansion of TCP gene family in G. raimondii. Moreover, the expression profiles of TCP genes shed light on their functional divergence.

  1. Genome-wide identification and expression analysis of TCP transcription factors in Gossypium raimondii

    PubMed Central

    Ma, Jun; Wang, Qinglian; Sun, Runrun; Xie, Fuliang; Jones, Don C.; Zhang, Baohong

    2014-01-01

    Plant-specific TEOSINTE-BRANCHED1/CYCLOIDEA/PCF (TCP) transcription factors play versatile functions in multiple aspects of plant growth and development. However, no systematical study has been performed in cotton. In this study, we performed for the first time the genome-wide identification and expression analysis of the TCP transcription factor family in Gossypium raimondii. A total of 38 non-redundant cotton TCP encoding genes were identified. The TCP transcription factors were divided into eleven subgroups based on phylogenetic analysis. Most TCP genes within the same subfamily demonstrated similar exon and intron organization and the motif structures were highly conserved among the subfamilies. Additionally, the chromosomal distribution pattern revealed that TCP genes were unevenly distributed across 11 out of the 13 chromosomes; segmental duplication is a predominant duplication event for TCP genes and the major contributor to the expansion of TCP gene family in G. raimondii. Moreover, the expression profiles of TCP genes shed light on their functional divergence. PMID:25322260

  2. ACTS 118x: High Speed TCP Interoperability Testing

    NASA Technical Reports Server (NTRS)

    Brooks, David E.; Buffinton, Craig; Beering, Dave R.; Welch, Arun; Ivancic, William D.; Zernic, Mike; Hoder, Douglas J.

    1999-01-01

    With the recent explosion of the Internet and the enormous business opportunities available to communication system providers, great interest has developed in improving the efficiency of data transfer over satellite links using the Transmission Control Protocol (TCP) of the Internet Protocol (IP) suite. The NASA's ACTS experiments program initiated a series of TCP experiments to demonstrate scalability of TCP/IP and determine to what extent the protocol can be optimized over a 622 Mbps satellite link. Through partnerships with the government technology oriented labs, computer, telecommunication, and satellite industries NASA Glenn was able to: (1) promote the development of interoperable, high-performance TCP/IP implementations across multiple computing / operating platforms; (2) work with the satellite industry to answer outstanding questions regarding the use of standard protocols (TCP/IP and ATM) for the delivery of advanced data services, and for use in spacecraft architectures; and (3) conduct a series of TCP/IP interoperability tests over OC12 ATM over a satellite network in a multi-vendor environment using ACTS. The experiments' various network configurations and the results are presented.

  3. Discrete time modeling and stability analysis of TCP Vegas

    NASA Astrophysics Data System (ADS)

    You, Byungyong; Koo, Kyungmo; Lee, Jin S.

    2007-12-01

    This paper presents an analysis method for TCP Vegas network model with single link and single source. Some papers showed global stability of several network models, but those models are not a dual problem where dynamics both exist in sources and links such as TCP Vegas. Other papers studied TCP Vegas as a dual problem, but it did not fully derive an asymptotic stability region. Therefore we analyze TCP Vegas with Jury's criterion which is necessary and sufficient condition. So we use state space model in discrete time and by using Jury's criterion, we could find an asymptotic stability region of TCP Vegas network model. This result is verified by ns-2 simulation. And by comparing with other results, we could know our method performed well.

  4. In vitro testing of calcium phosphate (HA, TCP, and biphasic HA-TCP) whiskers.

    PubMed

    Jalota, Sahil; Bhaduri, Sarit B; Tas, A Cuneyt

    2006-09-01

    Calcium phosphate [single-phase hydroxyapatite (HA, Ca(10)(PO(4))(6)(OH)(2)), single-phase tricalcium phosphate (beta-TCP, Ca(3)(PO(4))(2)), and biphasic HA-TCP] whiskers were formed by using a novel microwave-assisted molten salt mediated process. Aqueous solutions containing NaNO(3), HNO(3), Ca(NO(3))(2) x 4H(2)O, and KH(2)PO(4) (with or without urea) were used as starting reagents. These solutions were irradiated in a household microwave oven for 5 min. As-recovered precursors were then simply stirred in water at room temperature for 1 h to obtain the whiskers of the desired calcium phosphate (CaP) bioceramics. These whiskers were evaluated, respectively, in vitro by (1) soaking those in synthetic body fluid (SBF) solutions at 37 degrees C for one week, and (2) performing cell attachment and total protein assay tests on the neat whiskers by using a mouse osteoblast cell line (7F2). beta-TCP, HA, and HA-TCP biphasic whiskers were all found to possess apatite-inducing ability when soaked in SBF. SBF-soaked whiskers were found to have BET surface areas ranging from 45 to 112 m(2)/g. Although the osteoblast viability and protein concentrations were found to be the highest on the neat HA whiskers, cells were attached and proliferated on all the whiskers.

  5. A Randomized Clinical Trial Evaluating rh-FGF-2/β-TCP in Periodontal Defects.

    PubMed

    Cochran, D L; Oh, T-J; Mills, M P; Clem, D S; McClain, P K; Schallhorn, R A; McGuire, M K; Scheyer, E T; Giannobile, W V; Reddy, M S; Abou-Arraj, R V; Vassilopoulos, P J; Genco, R J; Geurs, N C; Takemura, A

    2016-05-01

    Biological mediators have been used to enhance periodontal regeneration. The aim of this prospective randomized controlled study was to evaluate the safety and effectiveness of 3 doses of fibroblast growth factor 2 (FGF-2) when combined with a β-tricalcium phosphate (β-TCP) scaffold carrier placed in vertical infrabony periodontal defects in adult patients. In this double-blinded, dose-verification, externally monitored clinical study, 88 patients who required surgical intervention to treat a qualifying infrabony periodontal defect were randomized to 1 of 4 treatment groups-β-TCP alone (control) and 0.1% recombinant human FGF-2 (rh-FGF-2), 0.3% rh-FGF-2, and 0.4% rh-FGF-2 with β-TCP-following scaling and root planing of the tooth prior to a surgical appointment. Flap surgery was performed with EDTA conditioning of the root prior to device implantation. There were no statistically significant differences in patient demographics and baseline characteristics among the 4 treatment groups. When a composite outcome of gain in clinical attachment of 1.5 mm was used with a linear bone growth of 2.5 mm, a dose response pattern detected a plateau in the 0.3% and 0.4% rh-FGF-2/β-TCP groups with significant improvements over control and 0.1% rh-FGF-2/β-TCP groups. The success rate at 6 mo was 71% in the 2 higher-concentration groups, as compared with 45% in the control and lowest treatment groups. Percentage bone fill in the 2 higher-concentration groups was 75% and 71%, compared with 63% and 61% in the control and lowest treatment group. No increases in specific antibody to rh-FGF-2 were detected, and no serious adverse events related to the products were reported. The results from this multicenter trial demonstrated that the treatment of infrabony vertical periodontal defects can be enhanced with the addition of rh-FGF-2/β-TCP (ClinicalTrials.gov NCT01728844). © International & American Associations for Dental Research 2016.

  6. Expression of caveolin-1 in the early phase of beta-TCP implanted in dog mandible.

    PubMed

    Chou, Cherng-Tzeh; Bhawal, Ujjal K; Watanabe, Nobuyuki; Kuboyama, Noboru; Chang, Wei-Jen; Lee, Sheng-Yang; Abiko, Yoshimitsu

    2013-07-01

    Caveolin is an essential and signature protein of caveolae. Caveolin-1 participates in signal transduction processes by acting as a scaffolding protein that concentrates, organizes and functional regulates signalling molecules within caveolar membranes. Beta-tricalcium phosphate (β-TCP) has been widely used for scaffold in tissue engineering due to its high biodegradability, osteoconductivity, easy manipulation, and lack of histotoxicity. To better understand the role of caveolin-1 in bone homeostasis and response to β-TCP scaffold, β-TCP was implanted into the dog mandible defects in beagle dogs, and gene expression profiles were examined focused on the molecular components involved in caveolin-1 regulation. Here we showed the quantitative imageology analysis characterized using in vivo micro-computed tomography (CT) images at 4 and 7 days after β-TCP implanted in dog mandibles. The bone reformation by using the β-TCP scaffolds began within 4 days of surgery, and was healing well at 7 days after surgery. Higher mRNA level of caveolin-1 was observed in β-TCP-implanted Beagle dog mandibles compared with controls at day 4 and day 7 post-surgery. The enhancement of caveolin-1 by β-TCP was further confirmed by immunohistochemistry and immunofluorescence analysis. We further revealed increased Smad7 and Phospho Stat3 expression in β-TCP-implanted specimens. Taken together, these results suggest that the enhancement of caveolin-1 play an important role in accelerating bone formation by β-TCP. Copyright © 2013 Wiley Periodicals, Inc.

  7. Enhanced bone regeneration composite scaffolds of PLLA/β-TCP matrix grafted with gelatin and HAp.

    PubMed

    Wang, Jie-Lin; Chen, Qian; Du, Bei-Bei; Cao, Lu; Lin, Hong; Fan, Zhong-Yong; Dong, Jian

    2018-06-01

    The composite polylactide PLLA/β-TCP scaffolds were fabricated by solution casting and were coated with gelatin/hydroxyapatite (Gel/HAp) to improve the biological properties of the composite scaffolds. The Gel/HAp mixture was prepared using an in situ reaction, and a grafting-coating method was used to increase the efficiency of coating the PLLA/β-TCP matrix with Gel/HAp. First, free amino groups were introduced by 1,6-hexanediamine to aminolyze the PLLA/β-TCP matrix surface. Second, glutaraldehyde was coupled to Gel/HAp as a crosslinking agent. The structure and properties of Gel/HAp-modified PLLA/β-TCP films were characterized by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and water contact angle measurements (WCA). The experimental results show that 23 wt% HAp was uniformly dispersed in the gelatin coating by in situ synthesis. The Gel/HAp composite coating was successfully immobilized on the aminolyzed PLLA/β-TCP surface via a chemical grafting method, which promoted a lower degradation rate and was more hydrophilic than a physical grafting method. The Gel/HAp composite coating adhered tightly and homogeneously to the hydrophobic PLLA/β-TCP surface. Moreover, mouse embryo osteoblast precursor (MC3T3-E1) cells grown on the scaffolds were behaviorally and morphologically characterized. The results indicated that the Gel/HAp composite coating was favorable for the attachment and proliferation of preosteoblasts and that Gel/HAp-NH-PLLA/β-TCP would be a candidate scaffold for bone repair. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Latency of TCP applications over the ATM-WAN using the GFR service category

    NASA Astrophysics Data System (ADS)

    Chen, Kuo-Hsien; Siliquini, John F.; Budrikis, Zigmantas

    1998-10-01

    The GFR service category has been proposed for data services in ATM networks. Since users are ultimately interested in data service that provide high efficiency and low latency, it is important to study the latency performance for data traffic of the GFR service category in an ATM network. Today much of the data traffic utilizes the TCP/IP protocol suite and in this paper we study through simulation the latency of TCP applications running over a wide-area ATM network utilizing the GFR service category using a realistic TCP traffic model. From this study, we find that during congestion periods the reserved bandwidth in GFR can improve the latency performance for TCP applications. However, due to TCP 'Slow Start' data segment generation dynamics, we show that a large proportion of TCP segments are discarded under network congestion even when the reserved bandwidth is equal to the average generated rate of user data. Therefore, a user experiences worse than expected latency performance when the network is congested. In this study we also examine the effects of segment size on the latency performance of TCP applications using the GFR service category.

  9. Mechanism of lubrication by tricresylphosphate (TCP)

    NASA Technical Reports Server (NTRS)

    Faut, O. D.; Wheeler, D. R.

    1983-01-01

    A pin-on-disk tribometer equipped with an induction heater was used to study the coefficient of friction as a function of temperature for tricresylphosphate (TCP) on continuous vacuum melted (CVM) M-50 tool steel when the TCP was present in a liquid reservoir (bulk lubrication), and when it was applied as a liquid layer directly to the disk (limited lubrication). Under limited lubrication conditions, experiments were performed in dry ( 100 ppm H2O) air, dry ( 20 ppm H2O) nitrogen, dry nitrogen with the disks heated to 700 C then cooled to room temperature before the TCP was applied and the measurements made (preheated disks), and moist nitrogen using preheated disks. When the coefficient of friction was plotted as a function of the disk temperature, the friction decreased at a characteristic temperature, T sub r whose observed values were 265 C for bulk lubrication conditions in dry air, 225 C for limited lubrication conditions in dry air, and 215 C for limited lubrication conditions in dry nitrogen. No decrease in friction was observed with preheated disks; instead a sharp failure temperature was observed at 218 C, which was taken as the temperature about which the behavior of TCP should be judged, X-ray photoelectron spectroscopy confirmed the presence of phosphate on the surface of the iron pins used in the tribometer under TCP lubrication. Depth profile studies support the idea that a chemical reaction occurs between the TCP and the metal surface at T sub r.

  10. Identification, cloning and characterization of the tomato TCP transcription factor family.

    PubMed

    Parapunova, Violeta; Busscher, Marco; Busscher-Lange, Jacqueline; Lammers, Michiel; Karlova, Rumyana; Bovy, Arnaud G; Angenent, Gerco C; de Maagd, Ruud A

    2014-06-06

    TCP proteins are plant-specific transcription factors, which are known to have a wide range of functions in different plant species such as in leaf development, flower symmetry, shoot branching, and senescence. Only a small number of TCP genes has been characterised from tomato (Solanum lycopersicum). Here we report several functional features of the members of the entire family present in the tomato genome. We have identified 30 Solanum lycopersicum SlTCP genes, most of which have not been described before. Phylogenetic analysis clearly distinguishes two homology classes of the SlTCP transcription factor family - class I and class II. Class II differentiates in two subclasses, the CIN-TCP subclass and the CYC/TB1 subclass, involved in leaf development and axillary shoots formation, respectively. The expression patterns of all members were determined by quantitative PCR. Several SlTCP genes, like SlTCP12, SlTCP15 and SlTCP18 are preferentially expressed in the tomato fruit, suggesting a role during fruit development or ripening. These genes are regulated by RIN (RIPENING INHIBITOR), CNR (COLORLESS NON-RIPENING) and SlAP2a (APETALA2a) proteins, which are transcription factors with key roles in ripening. With a yeast one-hybrid assay we demonstrated that RIN binds the promoter fragments of SlTCP12, SlTCP15 and SlTCP18, and that CNR binds the SlTCP18 promoter. This data strongly suggests that these class I SlTCP proteins are involved in ripening. Furthermore, we demonstrate that SlTCPs bind the promoter fragments of members of their own family, indicating that they regulate each other. Additional yeast one-hybrid studies performed with Arabidopsis transcription factors revealed binding of the promoter fragments by proteins involved in the ethylene signal transduction pathway, contributing to the idea that these SlTCP genes are involved in the ripening process. Yeast two-hybrid data shows that SlTCP proteins can form homo and heterodimers, suggesting that they act

  11. Identification, cloning and characterization of the tomato TCP transcription factor family

    PubMed Central

    2014-01-01

    Background TCP proteins are plant-specific transcription factors, which are known to have a wide range of functions in different plant species such as in leaf development, flower symmetry, shoot branching, and senescence. Only a small number of TCP genes has been characterised from tomato (Solanum lycopersicum). Here we report several functional features of the members of the entire family present in the tomato genome. Results We have identified 30 Solanum lycopersicum SlTCP genes, most of which have not been described before. Phylogenetic analysis clearly distinguishes two homology classes of the SlTCP transcription factor family - class I and class II. Class II differentiates in two subclasses, the CIN-TCP subclass and the CYC/TB1 subclass, involved in leaf development and axillary shoots formation, respectively. The expression patterns of all members were determined by quantitative PCR. Several SlTCP genes, like SlTCP12, SlTCP15 and SlTCP18 are preferentially expressed in the tomato fruit, suggesting a role during fruit development or ripening. These genes are regulated by RIN (RIPENING INHIBITOR), CNR (COLORLESS NON-RIPENING) and SlAP2a (APETALA2a) proteins, which are transcription factors with key roles in ripening. With a yeast one-hybrid assay we demonstrated that RIN binds the promoter fragments of SlTCP12, SlTCP15 and SlTCP18, and that CNR binds the SlTCP18 promoter. This data strongly suggests that these class I SlTCP proteins are involved in ripening. Furthermore, we demonstrate that SlTCPs bind the promoter fragments of members of their own family, indicating that they regulate each other. Additional yeast one-hybrid studies performed with Arabidopsis transcription factors revealed binding of the promoter fragments by proteins involved in the ethylene signal transduction pathway, contributing to the idea that these SlTCP genes are involved in the ripening process. Yeast two-hybrid data shows that SlTCP proteins can form homo and heterodimers, suggesting

  12. The cotton transcription factor TCP14 functions in auxin-mediated epidermal cell differentiation and elongation.

    PubMed

    Wang, Miao-Ying; Zhao, Pi-Ming; Cheng, Huan-Qing; Han, Li-Bo; Wu, Xiao-Min; Gao, Peng; Wang, Hai-Yun; Yang, Chun-Lin; Zhong, Nai-Qin; Zuo, Jian-Ru; Xia, Gui-Xian

    2013-07-01

    Plant-specific TEOSINTE-BRANCHED1/CYCLOIDEA/PCF (TCP) transcription factors play crucial roles in development, but their functional mechanisms remain largely unknown. Here, we characterized the cellular functions of the class I TCP transcription factor GhTCP14 from upland cotton (Gossypium hirsutum). GhTCP14 is expressed predominantly in fiber cells, especially at the initiation and elongation stages of development, and its expression increased in response to exogenous auxin. Induced heterologous overexpression of GhTCP14 in Arabidopsis (Arabidopsis thaliana) enhanced initiation and elongation of trichomes and root hairs. In addition, root gravitropism was severely affected, similar to mutant of the auxin efflux carrier PIN-FORMED2 (PIN2) gene. Examination of auxin distribution in GhTCP14-expressing Arabidopsis by observation of auxin-responsive reporters revealed substantial alterations in auxin distribution in sepal trichomes and root cortical regions. Consistent with these changes, expression of the auxin uptake carrier AUXIN1 (AUX1) was up-regulated and PIN2 expression was down-regulated in the GhTCP14-expressing plants. The association of GhTCP14 with auxin responses was also evidenced by the enhanced expression of auxin response gene IAA3, a gene in the AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) family. Electrophoretic mobility shift assays showed that GhTCP14 bound the promoters of PIN2, IAA3, and AUX1, and transactivation assays indicated that GhTCP14 had transcription activation activity. Taken together, these results demonstrate that GhTCP14 is a dual-function transcription factor able to positively or negatively regulate expression of auxin response and transporter genes, thus potentially acting as a crucial regulator in auxin-mediated differentiation and elongation of cotton fiber cells.

  13. RABBIT EARS regulates the transcription of TCP4 during petal development in Arabidopsis.

    PubMed

    Li, Jing; Wang, Yanzhi; Zhang, Yongxia; Wang, Weiyao; Irish, Vivian F; Huang, Tengbo

    2016-12-01

    Plant organ growth requires the proper transition from cell proliferation to cell expansion and differentiation. The CIN-TCP transcription factor gene TCP4 and its post-transcriptional regulator microRNA319 play a pivotal role in this process. In this study, we identified a pathway in which the product of the C2H2 zinc finger gene RABBIT EARS (RBE) regulates the transcription of TCP4 during Arabidopsis (Arabidopsis thaliana) petal development. RBE directly represses TCP4 during the early stages of petal development; this contributes to the role of RBE in controlling the growth of petal primordia. We also found that the rbe-1 mutant strongly enhanced the petal phenotypes of tcp4soj6 and mir319a, two mutants with compromised miR319 regulation of TCP4 Our results show that transcriptional and post-transcriptional regulation function together to pattern the spatial and temporal expression of TCP4 This in turn controls petal size and shape in Arabidopsis. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  14. Improvement of β-TCP/PLLA biodegradable material by surface modification with stearic acid.

    PubMed

    Ma, Fengcang; Chen, Sai; Liu, Ping; Geng, Fang; Li, Wei; Liu, Xinkuan; He, Daihua; Pan, Deng

    2016-05-01

    Poly-L-lactide (PLLA) is a biodegradable polymer and used widely. Incorporation of beta tricalcium phosphate (β-TCP) into PLLA can enhance its osteoinductive properties. But the interfacial layer between β-TCP particles with PLLA matrix is easy to be destroyed due to inferior interfacial compatibility of the organic/inorganic material. In this work, a method of β-TCP surface modification with stearic acid was investigated to improve the β-TCP/PLLA biomaterial. The effects of surface modification on the β-TCP were investigated by FTIR, XPS, TGA and CA. It was found that the stearic acid reacted with β-TCP and oxhydryl was formed during the surface modification. Hydrophilicity of untreated or modified β-TCP/PLLA composite was increased by the addition of 10 wt.% β-TCP, but it decreased as the addition amount increased from 10 wt.% to 20 wt.%. Two models were suggested to describe the effect of β-TCP concentration on CA of the composites. Mechanical properties of β-TCP/PLLA composites were tested by bending and tensile tests. Fractures of the composites after mechanical test were observed by SEM. It was found that surface modification with stearic acid improved bending and tensile strengths of the β-TCP/PLLA composites obviously. The SEM results indicated that surface modification decreased the probability of interface debonding between fillers and matrix under load. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Research on TCP/IP network communication based on Node.js

    NASA Astrophysics Data System (ADS)

    Huang, Jing; Cai, Lixiong

    2018-04-01

    In the face of big data, long connection and high synchronization, TCP/IP network communication will cause performance bottlenecks due to its blocking multi-threading service model. This paper presents a method of TCP/IP network communication protocol based on Node.js. On the basis of analyzing the characteristics of Node.js architecture and asynchronous non-blocking I/O model, the principle of its efficiency is discussed, and then compare and analyze the network communication model of TCP/IP protocol to expound the reasons why TCP/IP protocol stack is widely used in network communication. Finally, according to the large data and high concurrency in the large-scale grape growing environment monitoring process, a TCP server design based on Node.js is completed. The results show that the example runs stably and efficiently.

  16. SCPS-TP, TCP, and Rate-Based Protocol Evaluation. Revised

    NASA Technical Reports Server (NTRS)

    Tran, Diepchi T.; Lawas-Grodek, Frances J.; Dimond, Robert P.; Ivancic, William D.

    2005-01-01

    Tests were performed at Glenn Research Center to compare the performance of the Space Communications Protocol Standard Transport Protocol (SCPS TP, otherwise known as "TCP Tranquility") relative to other variants of TCP and to determine the implementation maturity level of these protocols, particularly for higher speeds. The testing was performed over reasonably high data rates of up to 100 Mbps with delays that are characteristic of near-planetary environments. The tests were run for a fixed packet size, but for variously errored environments. This report documents the testing performed to date.

  17. Measuring and Evaluating TCP Splitting for Cloud Services

    NASA Astrophysics Data System (ADS)

    Pathak, Abhinav; Wang, Y. Angela; Huang, Cheng; Greenberg, Albert; Hu, Y. Charlie; Kern, Randy; Li, Jin; Ross, Keith W.

    In this paper, we examine the benefits of split-TCP proxies, deployed in an operational world-wide network, for accelerating cloud services. We consider a fraction of a network consisting of a large number of satellite datacenters, which host split-TCP proxies, and a smaller number of mega datacenters, which ultimately perform computation or provide storage. Using web search as an exemplary case study, our detailed measurements reveal that a vanilla TCP splitting solution deployed at the satellite DCs reduces the 95 th percentile of latency by as much as 43% when compared to serving queries directly from the mega DCs. Through careful dissection of the measurement results, we characterize how individual components, including proxy stacks, network protocols, packet losses and network load, can impact the latency. Finally, we shed light on further optimizations that can fully realize the potential of the TCP splitting solution.

  18. The Behavior of TCP and Its Extensions in Space

    NASA Technical Reports Server (NTRS)

    Wang, Ruhai; Horan, Stephen

    2001-01-01

    The performance of Transmission Control Protocol (TCP) in space has been examined from the observations of simulation and experimental tests for several years at National Aeronautics and Space Administration (NASA), Department of Defense (DoD) and universities. At New Mexico State University (NMSU), we have been concentrating on studying the performance of two protocol suites: the file transfer protocol (ftp) running over Transmission Control Protocol/Internet Protocol (TCP/IP) stack and the file protocol (fp) running over the Space Communications Protocol Standards (SCPS)-Transport Protocol (TP) developed under the Consultative Committee for Space Data Systems (CCSDS) standards process. SCPS-TP is considered to be TCP's extensions for space communications. This dissertation experimentally studies the behavior of TCP and SCPS-TP by running the protocol suites over both the Space-to-Ground Link Simulator (SGLS) test-bed and realistic satellite link. The study concentrates on comparing protocol behavior by plotting the averaged file transfer times for different experimental configurations and analyzing them using Statistical Analysis System (SAS) based procedures. The effects of different link delays and various Bit-Error-Rates (BERS) on each protocol performance are also studied and linear regression models are built for experiments over SGLS test-bed to reflect the relationships between the file transfer time and various transmission conditions.

  19. Characterization of TCP-1 probes for molecular imaging of colon cancer.

    PubMed

    Liu, Zhonglin; Gray, Brian D; Barber, Christy; Bernas, Michael; Cai, Minying; Furenlid, Lars R; Rouse, Andrew; Patel, Charmi; Banerjee, Bhaskar; Liang, Rongguang; Gmitro, Arthur F; Witte, Marlys H; Pak, Koon Y; Woolfenden, James M

    2016-10-10

    Molecular probes capable of detecting colorectal cancer (CRC) are needed for early CRC diagnosis. The objective of this study was to characterize c[CTPSPFSHC]OH (TCP-1), a small peptide derived from phage display selection, for targeting human CRC xenografts using technetium-99m ((99m)Tc)-labeled TCP-1 and fluorescent cyanine-7 (Cy7)-labeled form of the peptide (Cy7-TCP-1). (99m)Tc-TCP-1 was generated by modifying TCP-1 with succinimidyl-6-hydrazino-nicotinamide (S-HYNIC) followed by radiolabeling. In vitro saturation binding experiments were performed for (99m)Tc-TCP-1 in human HCT116 colon cancer cells. SCID mice with human HCT116 cancer xenografts were imaged with (99m)Tc-TCP-1 or control peptide using a small-animal SPECT imager: Group I (n=5) received no blockade; Group II (n=5) received a blocking dose of non-radiolabeled TCP-1. Group III (n=5) were imaged with (99m)Tc-labeled control peptide (inactive peptide). SCID mice with human PC3 prostate cancer xenografts (Group IV, n=5) were also imaged with (99m)Tc-TCP-1. Eight additional SCID mice bearing HCT116 xenografts in dorsal skinfold window chambers (DSWC) were imaged by direct positron imaging of (18)F-fluorodeoxyglucose ((18)F-FDG) and fluorescence microscopy of Cy7-TCP-1. In vitro(99m)Tc-HYNIC-TCP-1 binding assays on HCT 116 cells indicated a mean Kd of 3.04±0.52nM. In cancer xenografts, (99m)Tc-TCP-1 radioactivity (%ID/g) was 1.01±0.15 in the absence of blockade and was reduced to 0.26±0.04 (P<0.01) with blockade. No radioactive uptake was observed in the PC3 tumors with (99m)Tc-TCP-1 or HCT116 tumors with inactive peptide. Cy7-TCP-1 activity localized not only in metabolically active tumors, as defined by (18)F-FDG imaging, but also in peritumoral microvasculature. In conclusion, TCP-1 probes may have a distinct targeting mechanism with high selectivity for CRC and tumor-associated vasculature. Molecular imaging with TCP-1 probes appears promising to detect malignant colorectal lesions. Copyright

  20. The Arabidopsis class I TCP transcription factor AtTCP11 is a developmental regulator with distinct DNA-binding properties due to the presence of a threonine residue at position 15 of the TCP domain.

    PubMed

    Viola, Ivana L; Uberti Manassero, Nora G; Ripoll, Rodrigo; Gonzalez, Daniel H

    2011-04-01

    The TCP domain is a DNA-binding domain present in plant transcription factors that modulate different processes. In the present study, we show that Arabidopsis class I TCP proteins are able to interact with a dyad-symmetric sequence composed of two GTGGG half-sites. TCP20 establishes symmetric interactions with the 5' half of each strand, whereas TCP11 interacts mainly with the 3' half. SELEX (systematic evolution of ligands by exponential enrichment) experiments with TCP15 and TCP20 indicated that these proteins have similar, although not identical, DNA-binding preferences and are able to interact with non-palindromic binding sites of the type GTGGGNCCNN. TCP11 shows a different DNA-binding specificity, with a preference for the sequence GTGGGCCNNN. The distinct DNA-binding properties of TCP11 are due to the presence of a threonine residue at position 15 of the TCP domain, a position that is occupied by an arginine residue in most TCP proteins. TCP11 also forms heterodimers with TCP15 that have increased DNA-binding efficiency. The expression in plants of a repressor form of TCP11 demonstrated that this protein is a developmental regulator that influences the growth of leaves, stems and petioles, and pollen development. The results suggest that changes in DNA-binding preferences may be one of the mechanisms through which class I TCP proteins achieve functional specificity.

  1. ß-TCP bone substitutes in tibial plateau depression fractures.

    PubMed

    Rolvien, Tim; Barvencik, Florian; Klatte, Till Orla; Busse, Björn; Hahn, Michael; Rueger, Johannes Maria; Rupprecht, Martin

    2017-10-01

    The use of beta-tricalciumphospate (ß-TCP, Cerasorb®) ceramics as an alternative for autologous bone-grafting has been outlined previously, however with no study focusing on both clinical and histological outcomes of ß-TCP application in patients with multi-fragment tibial plateau fractures. The aim of this study was to analyze the long-term results of ß-TCP in patients with tibial plateau fractures. 52 patients were included in this study. All patients underwent open surgery with ß-TCP block or granulate application. After a mean follow-up of 36months (14-64months), the patients were reviewed. Radiography and computed-tomography were performed, while the Rasmussen score was obtained for clinical outcome. Furthermore, seven patients underwent biopsy during hardware removal, which was subsequently analyzed by histology and backscattered electron microscopy (BSEM). An excellent reduction with two millimeters or less of residual incongruity was achieved in 83% of the patients. At follow-up, no further changes occurred and no nonunions were observed. Functional outcome was good to excellent in 82%. Four patients underwent revision surgery due to reasons unrelated to the bone substitute material. Histologic analyses indicated that new bone was built around the ß-TCP-grafts, however a complete resorption of ß-TCP was not observed. ß-TCP combined with internal fixation represents an effective and safe treatment of tibial plateau depression fractures with good functional recovery. While its osteoconductivity seems to be successful, the biological degradation and replacement of ß-TCP is less pronounced in humans than previous animal studies have indicated. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Fabrication of dicalcium phosphate dihydrate-coated β-TCP granules and evaluation of their osteoconductivity using experimental rats.

    PubMed

    Shariff, Khairul Anuar; Tsuru, Kanji; Ishikawa, Kunio

    2017-06-01

    β-Tricalcium phosphate (β-TCP) has attracted much attention as an artificial bone substitute owing to its biocompatibility and osteoconductivity. In this study, osteoconductivity of β-TCP bone substitute was enhanced without using growth factors or cells. Dicalcium phosphate dihydrate (DCPD), which is known to possess the highest solubility among calcium phosphates, was coated on β-TCP granules by exposing their surface with acidic calcium phosphate solution. The amount of coated DCPD was regulated by changing the reaction time between β-TCP granules and acidic calcium phosphate solution. Histomorphometry analysis obtained from histological results revealed that the approximately 10mol% DCPD-coated β-TCP granules showed the largest new bone formation compared to DCPD-free β-TCP granules, approximately 2.5mol% DCPD-coated β-TCP granules, or approximately 27mol% DCPD-coated β-TCP granules after 2 and 4weeks of implantation. Based on this finding, we demonstrate that the osteoconductivity of β-TCP granules could be improved by coating their surface with an appropriate amount of DCPD. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Class I TCP-DELLA interactions in inflorescence shoot apex determine plant height.

    PubMed

    Davière, Jean-Michel; Wild, Michael; Regnault, Thomas; Baumberger, Nicolas; Eisler, Herfried; Genschik, Pascal; Achard, Patrick

    2014-08-18

    Regulation of plant height, one of the most important agronomic traits, is the focus of intensive research for improving crop performance. Stem elongation takes place as a result of repeated cell divisions and subsequent elongation of cells produced by apical and intercalary meristems. The gibberellin (GA) phytohormones have long been known to control stem and internodal elongation by stimulating the degradation of nuclear growth-repressing DELLA proteins; however, the mechanism allowing GA-responsive growth is only slowly emerging. Here, we show that DELLAs directly regulate the activity of the plant-specific class I TCP transcription factor family, key regulators of cell proliferation. Our results demonstrate that class I TCP factors directly bind the promoters of core cell-cycle genes in Arabidopsis inflorescence shoot apices while DELLAs block TCP function by binding to their DNA-recognition domain. GAs antagonize such repression by promoting DELLA destruction and therefore cause a concomitant accumulation of TCP factors on promoters of cell-cycle genes. Consistent with this model, the quadruple mutant tcp8 tcp14 tcp15 tcp22 exhibits severe dwarfism and reduced responsiveness to GA action. Altogether, we conclude that GA-regulated DELLA-TCP interactions in inflorescence shoot apex provide a novel mechanism to control plant height. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. The Cotton Transcription Factor TCP14 Functions in Auxin-Mediated Epidermal Cell Differentiation and Elongation1[C][W

    PubMed Central

    Wang, Miao-Ying; Zhao, Pi-Ming; Cheng, Huan-Qing; Han, Li-Bo; Wu, Xiao-Min; Gao, Peng; Wang, Hai-Yun; Yang, Chun-Lin; Zhong, Nai-Qin; Zuo, Jian-Ru; Xia, Gui-Xian

    2013-01-01

    Plant-specific TEOSINTE-BRANCHED1/CYCLOIDEA/PCF (TCP) transcription factors play crucial roles in development, but their functional mechanisms remain largely unknown. Here, we characterized the cellular functions of the class I TCP transcription factor GhTCP14 from upland cotton (Gossypium hirsutum). GhTCP14 is expressed predominantly in fiber cells, especially at the initiation and elongation stages of development, and its expression increased in response to exogenous auxin. Induced heterologous overexpression of GhTCP14 in Arabidopsis (Arabidopsis thaliana) enhanced initiation and elongation of trichomes and root hairs. In addition, root gravitropism was severely affected, similar to mutant of the auxin efflux carrier PIN-FORMED2 (PIN2) gene. Examination of auxin distribution in GhTCP14-expressing Arabidopsis by observation of auxin-responsive reporters revealed substantial alterations in auxin distribution in sepal trichomes and root cortical regions. Consistent with these changes, expression of the auxin uptake carrier AUXIN1 (AUX1) was up-regulated and PIN2 expression was down-regulated in the GhTCP14-expressing plants. The association of GhTCP14 with auxin responses was also evidenced by the enhanced expression of auxin response gene IAA3, a gene in the AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) family. Electrophoretic mobility shift assays showed that GhTCP14 bound the promoters of PIN2, IAA3, and AUX1, and transactivation assays indicated that GhTCP14 had transcription activation activity. Taken together, these results demonstrate that GhTCP14 is a dual-function transcription factor able to positively or negatively regulate expression of auxin response and transporter genes, thus potentially acting as a crucial regulator in auxin-mediated differentiation and elongation of cotton fiber cells. PMID:23715527

  5. TCP4-dependent induction of CONSTANS transcription requires GIGANTEA in photoperiodic flowering in Arabidopsis

    PubMed Central

    Shim, Jae Sung; Song, Yong Hun; Laboy Cintrón, Dianne; Koyama, Tomotsugu; Ohme-Takagi, Masaru; Pruneda-Paz, Jose L.; Kay, Steve A.; MacCoss, Michael J.

    2017-01-01

    Photoperiod is one of the most reliable environmental cues for plants to regulate flowering timing. In Arabidopsis thaliana, CONSTANS (CO) transcription factor plays a central role in regulating photoperiodic flowering. In contrast to posttranslational regulation of CO protein, still little was known about CO transcriptional regulation. Here we show that the CINCINNATA (CIN) clade of class II TEOSINTE BRANCHED 1/ CYCLOIDEA/ PROLIFERATING CELL NUCLEAR ANTIGEN FACTOR (TCP) proteins act as CO activators. Our yeast one-hybrid analysis revealed that class II CIN-TCPs, including TCP4, bind to the CO promoter. TCP4 induces CO expression around dusk by directly associating with the CO promoter in vivo. In addition, TCP4 binds to another flowering regulator, GIGANTEA (GI), in the nucleus, and induces CO expression in a GI-dependent manner. The physical association of TCP4 with the CO promoter was reduced in the gi mutant, suggesting that GI may enhance the DNA-binding ability of TCP4. Our tandem affinity purification coupled with mass spectrometry (TAP-MS) analysis identified all class II CIN-TCPs as the components of the in vivo TCP4 complex, and the gi mutant did not alter the composition of the TCP4 complex. Taken together, our results demonstrate a novel function of CIN-TCPs as photoperiodic flowering regulators, which may contribute to coordinating plant development with flowering regulation. PMID:28628608

  6. TCP4-dependent induction of CONSTANS transcription requires GIGANTEA in photoperiodic flowering in Arabidopsis.

    PubMed

    Kubota, Akane; Ito, Shogo; Shim, Jae Sung; Johnson, Richard S; Song, Yong Hun; Breton, Ghislain; Goralogia, Greg S; Kwon, Michael S; Laboy Cintrón, Dianne; Koyama, Tomotsugu; Ohme-Takagi, Masaru; Pruneda-Paz, Jose L; Kay, Steve A; MacCoss, Michael J; Imaizumi, Takato

    2017-06-01

    Photoperiod is one of the most reliable environmental cues for plants to regulate flowering timing. In Arabidopsis thaliana, CONSTANS (CO) transcription factor plays a central role in regulating photoperiodic flowering. In contrast to posttranslational regulation of CO protein, still little was known about CO transcriptional regulation. Here we show that the CINCINNATA (CIN) clade of class II TEOSINTE BRANCHED 1/ CYCLOIDEA/ PROLIFERATING CELL NUCLEAR ANTIGEN FACTOR (TCP) proteins act as CO activators. Our yeast one-hybrid analysis revealed that class II CIN-TCPs, including TCP4, bind to the CO promoter. TCP4 induces CO expression around dusk by directly associating with the CO promoter in vivo. In addition, TCP4 binds to another flowering regulator, GIGANTEA (GI), in the nucleus, and induces CO expression in a GI-dependent manner. The physical association of TCP4 with the CO promoter was reduced in the gi mutant, suggesting that GI may enhance the DNA-binding ability of TCP4. Our tandem affinity purification coupled with mass spectrometry (TAP-MS) analysis identified all class II CIN-TCPs as the components of the in vivo TCP4 complex, and the gi mutant did not alter the composition of the TCP4 complex. Taken together, our results demonstrate a novel function of CIN-TCPs as photoperiodic flowering regulators, which may contribute to coordinating plant development with flowering regulation.

  7. Mechanism of lubrication by tricresylphosphate (TCP)

    NASA Technical Reports Server (NTRS)

    Faut, O. D.; Buckley, D. H.

    1984-01-01

    The coefficient of friction was measured as a function of temperature on a pin-on-disk tribometer. Pins and disks of 440C and 52100 steels were lubricated with tricresylphosphate (TCP), 3.45 percent TCP in squalene, and pure squalene. The M-50 pins and disks were lubricated with 3.45 percent TCP in squalene and pure squalene. Experiments were conducted under limited lubrication conditions in dry ( 100 ppm H2O) air and dry ( pp H2O) nitrogen at 50 rpm (equivalent to a sliding velocity of 13 cm sec) and a constant load of 9.8 N (1 kg). Characteristic temperatures T sub r were identified for TCP on 52100 steel and for squalene on M-50 and 52100 steels, where the friction decreased because of a chemical reaction between the lubricant and the metal surface. The behavior of squalene obscured the influence of 3.45 percent TCP solute on the friction of the system. Wear volume measurements demonstrated that wear was lowest at temperatures just above T sub r. Comparing the behavior of TCP on M-50, 440C, and 52100 steels revealed that the TCP either reacted to give T sub r behavior or produced initial failure in the temperature range 223 + or - 5 C.

  8. Fabrication of Porous α-TCP/Gellan Gum Scaffold for Bone Tissue Engineering.

    PubMed

    Wen, Jian; Kim, Ill Yong; Kikuta, Koichi; Ohtsuki, Chikara

    2016-03-01

    α-tricalcium phosphate (α-TCP, α-Ca3(PO4)2) receives great attention for bone repairing due to its biodegradability and capability of transformation to human bone's main inorganic components, hydroxyapatite (HAp). α-TCP porous scaffold is easily procurable by sintering of the low-temperature polymorph of TCP, β-TCR Still, porous body of α-TCP is too brittle to being handled and shaped, limiting its clinical application as implant materials. To improve mechanical properties of α-TCP porous scaffold, the present study focused on coating of a type of polysaccharides on α-TCP scaffolds. Gellan gum was chosen as the polysaccharide for coating because of its biodegradability as well as the potential acting as substrate for HAp deposition during hydration of α-TCP after exposure to body fluid. After coating of gellan gum on α-TCP scaffolds with porosity of 75 vol%, the compressive strength increased from 0.45 MPa to around 2.00 MPa. Among the coated scaffold, the maximum compressive strength, 3.97 MPa, was obtained on the scaffold with porosity of 63 vol%. Improvement of mechanical properties of α-TCP/gellan gum composites was achieved to show easy handling performance for a bone substitute for tissue repairing. The dissolving rate of the coated scaffolds was also controlled by adjusting the concentration of GG solutions.

  9. TCP Throughput Profiles Using Measurements over Dedicated Connections

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rao, Nageswara S.; Liu, Qiang; Sen, Satyabrata

    Wide-area data transfers in high-performance computing infrastructures are increasingly being carried over dynamically provisioned dedicated network connections that provide high capacities with no competing traffic. We present extensive TCP throughput measurements and time traces over a suite of physical and emulated 10 Gbps connections with 0-366 ms round-trip times (RTTs). Contrary to the general expectation, they show significant statistical and temporal variations, in addition to the overall dependencies on the congestion control mechanism, buffer size, and the number of parallel streams. We analyze several throughput profiles that have highly desirable concave regions wherein the throughput decreases slowly with RTTs, inmore » stark contrast to the convex profiles predicted by various TCP analytical models. We present a generic throughput model that abstracts the ramp-up and sustainment phases of TCP flows, which provides insights into qualitative trends observed in measurements across TCP variants: (i) slow-start followed by well-sustained throughput leads to concave regions; (ii) large buffers and multiple parallel streams expand the concave regions in addition to improving the throughput; and (iii) stable throughput dynamics, indicated by a smoother Poincare map and smaller Lyapunov exponents, lead to wider concave regions. These measurements and analytical results together enable us to select a TCP variant and its parameters for a given connection to achieve high throughput with statistical guarantees.« less

  10. Surface biofunctionalization of β-TCP blocks using aptamer 74 for bone tissue engineering.

    PubMed

    Ardjomandi, N; Huth, J; Stamov, D R; Henrich, A; Klein, C; Wendel, H-P; Reinert, S; Alexander, D

    2016-10-01

    Successful bone regeneration following oral and maxillofacial surgeries depends on efficient functionalization strategies that allow the recruitment of osteogenic progenitor cells at the tissue/implant interface. We have previously identified aptamer 74, which exhibited a binding affinity for osteogenically induced jaw periosteal cells (JPCs). In the present study, this aptamer was used for the surface biofunctionalization of β-tricalcium phosphate (β-TCP) blocks. Atomic force microscopy (AFM) measurements showed increased binding activity of aptamer 74 towards osteogenically induced JPCs compared to untreated controls. The immobilization efficiency of aptamer 74 was analyzed using the QuantiFluor ssDNA assay for 2D surfaces and by amino acid analysis for 3D β-TCP constructs. Following the successful immobilization of aptamer 74 in 2D culture wells and on 3D constructs, in vitro assays showed no significant differences in cell proliferation compared to unmodified surfaces. Interestingly, JPC mineralization was significantly higher on the 2D surfaces and higher cell adhesion was detected on the 3D constructs with immobilized aptamer. Herein, we report an established, biocompatible β-TCP matrix with surface immobilization of aptamer 74, which enhances properties such as cell adhesion on 3D constructs and mineralization on 2D surfaces. Further studies need to be performed to improve the immobilization efficiency and to develop a suitable approach for JPC mineralization growing within 3D β-TCP constructs. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Bone augmentation using a highly porous PLGA/β-TCP scaffold containing fibroblast growth factor-2.

    PubMed

    Yoshida, T; Miyaji, H; Otani, K; Inoue, K; Nakane, K; Nishimura, H; Ibara, A; Shimada, A; Ogawa, K; Nishida, E; Sugaya, T; Sun, L; Fugetsu, B; Kawanami, M

    2015-04-01

    Beta-tricalcium phosphate (β-TCP), a bio-absorbable ceramic, facilitates bone conductivity. We constructed a highly porous three-dimensional scaffold, using β-TCP, for bone tissue engineering and coated it with co-poly lactic acid/glycolic acid (PLGA) to improve the mechanical strength and biological performance. The aim of this study was to examine the effect of implantation of the PLGA/β-TCP scaffold loaded with fibroblast growth factor-2 (FGF-2) on bone augmentation. The β-TCP scaffold was fabricated by the replica method using polyurethane foam, then coated with PLGA. The PLGA/β-TCP scaffold was characterized by scanning electron miscroscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction, compressive testing, cell culture and a subcutaneous implant test. Subsequently, a bone-forming test was performed using 52 rats. The β-TCP scaffold, PLGA-coated scaffold, and β-TCP and PLGA-coated scaffolds loaded with FGF-2, were implanted into rat cranial bone. Histological observations were made at 10 and 35 d postsurgery. SEM and TEM observations showed a thin PLGA layer on the β-TCP particles after coating. High porosity (> 90%) of the scaffold was exhibited after PLGA coating, and the compressive strength of the PLGA/β-TCP scaffold was six-fold greater than that of the noncoated scaffold. Good biocompatibility of the PLGA/β-TCP scaffold was found in the culture and implant tests. Histological samples obtained following implantation of PLGA/β-TCP scaffold loaded with FGF-2 showed significant bone augmentation. The PLGA coating improved the mechanical strength of β-TCP scaffolds while maintaining high porosity and tissue compatibility. PLGA/β-TCP scaffolds, in combination with FGF-2, are bioeffective for bone augmentation. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. TCP3 interacts with R2R3-MYB proteins, promotes flavonoid biosynthesis and negatively regulates the auxin response in Arabidopsis thaliana.

    PubMed

    Li, Shutian; Zachgo, Sabine

    2013-12-01

    TCP proteins belong to the plant-specific bHLH transcription factor family, and function as key regulators of diverse developmental processes. Functional redundancy amongst family members and post-transcriptional down-regulation by miRJAW of several TCP genes complicate their functional characterization. Here, we explore the role of TCP3 by analyzing transgenic plants expressing miRJAW-resistant mTCP3 and dominant-negative TCP3SRDX. Seedlings and seeds of mTCP3 plants were found to hyper-accumulate flavonols, anthocyanins and proanthocyanidins, whereas levels of proanthocyanidins were slightly reduced in TCP3SRDX plants. R2R3-MYB proteins control not only early flavonoid biosynthetic steps but also activate late flavonoid biosynthetic genes by forming ternary R2R3-MYB/bHLH/WD40 (MBW) complexes. TCP3 interacted in yeast with R2R3-MYB proteins, which was further confirmed in planta using BiFC experiments. Yeast three-hybrid assays revealed that TCP3 significantly strengthened the transcriptional activation capacity of R2R3-MYBs bound by the bHLH protein TT8. Transcriptome analysis of mTCP3 and TCP3SRDX plants supported a role for TCP3 in enhancing flavonoid biosynthesis. Moreover, several auxin-related developmental abnormalities were observed in mTCP3 plants. Transcriptome data coupled with studies of an auxin response reporter and auxin efflux carriers showed that TCP3 negatively modulates the auxin response, probably by compromising auxin transport capacity. Genetic experiments revealed that the chalcone synthase mutant tt4-11 lacking flavonoid biosynthesis abrogated the auxin-related defects caused by mTCP3. Together, these data suggest that TCP3 interactions with R2R3-MYBs lead to enhanced flavonoid production, which further negatively modulates the auxin response. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

  13. Genetic mapping of secretion and functional determinants of the Vibrio cholerae TcpF colonization factor.

    PubMed

    Krebs, Shelly J; Kirn, Thomas J; Taylor, Ronald K

    2009-06-01

    Colonization of the human small intestine by Vibrio cholerae requires the type IV toxin-coregulated pilus (TCP). TcpF, which is encoded within the tcp operon, is secreted from the bacterial cell by the TCP apparatus and is also essential for colonization. Bacteria lacking tcpF are deficient in colonization, and anti-TcpF antibodies are protective in the infant mouse cholera model. In order to elucidate the regions of the protein that are required for secretion through the TCP apparatus and for its function in colonization, random mutagenesis of tcpF was performed. Analysis of these mutants suggests that multiple regions throughout the protein influence extracellular secretion and that determinants near the C terminus are important for the function of TcpF in colonization. The TcpF proteins of certain environmental V. cholerae isolates with 31% to 66% identity to pathogenic V. cholerae TcpF showed higher similarity in regions identified as secretion determinants but diverged in regions found to be important for colonization. These environmental TcpF proteins are secreted from the pathogenic strain; however, they do not mediate colonization in the infant mouse model. Here we provide genetic evidence pointing toward regions of TcpF that influence secretion, as well as regions that play an important role in in vivo colonization.

  14. Redox-Dependent Modulation of Anthocyanin Biosynthesis by the TCP Transcription Factor TCP15 during Exposure to High Light Intensity Conditions in Arabidopsis.

    PubMed

    Viola, Ivana L; Camoirano, Alejandra; Gonzalez, Daniel H

    2016-01-01

    TCP proteins integrate a family of transcription factors involved in the regulation of developmental processes and hormone responses. It has been shown that most members of class I, one of the two classes in which the TCP family is divided, contain a conserved Cys that leads to inhibition of DNA binding when oxidized. In this work, we describe that the class-I TCP protein TCP15 inhibits anthocyanin accumulation during exposure of plants to high light intensity by modulating the expression of transcription factors involved in the induction of anthocyanin biosynthesis genes, as suggested by the study of plants that express TCP15 from the 35SCaMV promoter and mutants in TCP15 and the related gene TCP14. In addition, the effect of TCP15 on anthocyanin accumulation is lost after prolonged incubation under high light intensity conditions. We provide evidence that this is due to inactivation of TCP15 by oxidation of Cys-20 of the TCP domain. Thus, redox modulation of TCP15 activity in vivo by high light intensity may serve to adjust anthocyanin accumulation to the duration of exposure to high irradiation conditions. © 2016 American Society of Plant Biologists. All Rights Reserved.

  15. Effect of PDGF-BB and beta-tricalcium phosphate (β-TCP) on bone formation around dental implants: a pilot study in sheep.

    PubMed

    Choo, Tina; Marino, Victor; Bartold, P Mark

    2013-02-01

    The aim of this investigation was to examine the effect of a combination of purified recombinant human platelet-derived growth factor (rhPDGF-BB) mixed with a synthetic beta-tricalcium phosphate (β-TCP) on bone healing around dental implants with critical size circumferential defects. Three critical size circumferential defects were prepared in the ilium of six sheep. Three dental implants were placed into the centre of each defect and the 3.25 mm circumferential gap was filled with (a) blood clot alone; (b) β-TCP; (c) rhPDGF-BB (0.3 mg/ml) with β-TCP. All the defects in each group were covered with a Bio-Gide(®) resorbable barrier membrane. The sheep were sacrificed at 2 and 4 weeks and histological and histomorphometric analyses were performed to determine the percentage of new mineralized bone formation and residual β-TCP graft particles in the defects. Defects filled with rhPDGF-BB/β-TCP showed the highest rate of bone formation after 2 and 4 weeks with limited degradation of the β-TCP particles over 4 weeks. Defects filled with β-TCP showed the least bone fill after 2 and 4 weeks, and faster degradation of the β-TCP particles over 4 weeks compared with defects filled with rhPDGF-BB/β-TCP. Percentage of new mineralized bone was comparable in defects to blood clot alone and β-TCP after 4 weeks of healing, but there was a collapse in the defect area in defects with blood clot alone. In comparison, the space was maintained when β-TCP was used in defects at 4 weeks. Defects which had β-TCP alone showed an inhibition in bone healing at 2 and 4 weeks; however, the combination of rhPDGF-BB with β-TCP enhanced bone regeneration in these peri-implant bone defects at the same time intervals. © 2011 John Wiley & Sons A/S.

  16. MBG-Modified β-TCP Scaffold Promotes Mesenchymal Stem Cells Adhesion and Osteogenic Differentiation via a FAK/MAPK Signaling Pathway.

    PubMed

    Liu, Yutong; Ma, Yifan; Zhang, Jing; Xie, Qing; Wang, Zi; Yu, Shuang; Yuan, Yuan; Liu, Changsheng

    2017-09-13

    The β-TCP scaffold has been widely used as a bone graft substitute, but the traditional PMMA molding method-induced undesirable mechanical strength and poor interconnectivity still have not been addressed until now. In this study, a MBG-based PU foam templating method was developed to fabricate β-TCP scaffolds with desirable microtopography. The MBG gel, as both binder and modifier, prepared by a modified sol-gel method with controlled viscosity is incorporated with β-TCP powder and thereafter is impregnated into PU foam. The resultant hybrid scaffolds exhibited interconnected macropores (200-500 μm) and distinctive micropores (0.2-1.5 μm), especially for the TCP/25MBG (with 25 wt % content MBG). As expected, the compression strength of β-TCP/MBG composite scaffolds was enhanced with increasing MBG content, and TCP/50MBG (with 50 wt % content MBG) exhibited almost 100-fold enhancement compared to the pure β-TCP. Intriguingly, the cell affinity and osteogenic capacity of rBMSCs were also dramatically improved the best on TCP/25MBG. Further investigation found that the subtle, grainy-like microtopography, not the chemical composition, of the TCP/25MBG favored the adsorption of Fn and expression of integrin α5β1 and further facilitated FA formation and the expression of p-FAK, following activation of the MAPK/ERK signaling pathway and ultimately upregulated expression of osteogenic genes. Further in vivo experiments confirmed the promoted osteogenesis of TCP/25MBG in vivo. The results suggest that such a novel MBG-based PU foam templating method offers new guidance to construct hierarchically porous scaffolds, and the prepared MBG-modified β-TCP scaffold will have great potential for future use in bone tissue regeneration.

  17. On the Generation and Use of TCP Acknowledgments

    NASA Technical Reports Server (NTRS)

    Allman, Mark

    1998-01-01

    This paper presents a simulation study of various TCP acknowledgment generation and utilization techniques. We investigate the standard version of TCP and the two standard acknowledgment strategies employed by receivers: those that acknowledge each incoming segment and those that implement delayed acknowledgments. We show the delayed acknowledgment mechanism hurts TCP performance, especially during slow start. Next we examine three alternate mechanisms for generating and using acknowledgments designed to mitigate the negative impact of delayed acknowledgments. The first method is to generate delayed ACKs only when the sender is not using the slow start algorithm. The second mechanism, called byte counting, allows TCP senders to increase the amount of data being injected into the network based on the amount of data acknowledged rather than on the number of acknowledgments received. The last mechanism is a limited form of byte counting. Each of these mechanisms is evaluated in a simulated network with no competing traffic, as well as a dynamic environment with a varying amount of competing traffic. We study the costs and benefits of the alternate mechanisms when compared to the standard algorithm with delayed ACKs.

  18. SDTCP: Towards Datacenter TCP Congestion Control with SDN for IoT Applications

    PubMed Central

    Lu, Yifei; Ling, Zhen; Zhu, Shuhong; Tang, Ling

    2017-01-01

    The Internet of Things (IoT) has gained popularity in recent years. Today’s IoT applications are now increasingly deployed in cloud platforms to perform Big Data analytics. In cloud data center networks (DCN), TCP incast usually happens when multiple senders simultaneously communicate with a single receiver. However, when TCP incast happens, DCN may suffer from both throughput collapse for TCP burst flows and temporary starvation for TCP background flows. In this paper, we propose a software defined network (SDN)-based TCP congestion control mechanism, referred to as SDTCP, to leverage the features, e.g., centralized control methods and the global view of the network, in order to solve the TCP incast problems. When we detect network congestion on an OpenFlow switch, our controller can select the background flows and reduce their bandwidth by adjusting the advertised window of TCP ACK packets of the corresponding background flows so as to reserve more bandwidth for burst flows. SDTCP is transparent to the end systems and can accurately decelerate the rate of background flows by leveraging the global view of the network gained via SDN. The experiments demonstrate that our SDTCP can provide high tolerance for burst flows and achieve better flow completion time for short flows. Therefore, SDTCP is an effective and scalable solution for the TCP incast problem. PMID:28075347

  19. SDTCP: Towards Datacenter TCP Congestion Control with SDN for IoT Applications.

    PubMed

    Lu, Yifei; Ling, Zhen; Zhu, Shuhong; Tang, Ling

    2017-01-08

    The Internet of Things (IoT) has gained popularity in recent years. Today's IoT applications are now increasingly deployed in cloud platforms to perform Big Data analytics. In cloud data center networks (DCN), TCP incast usually happens when multiple senders simultaneously communicate with a single receiver. However, when TCP incast happens, DCN may suffer from both throughput collapse for TCP burst flows and temporary starvation for TCP background flows. In this paper, we propose a software defined network (SDN)-based TCP congestion control mechanism, referred to as SDTCP, to leverage the features, e.g., centralized control methods and the global view of the network, in order to solve the TCP incast problems. When we detect network congestion on an OpenFlow switch, our controller can select the background flows and reduce their bandwidth by adjusting the advertised window of TCP ACK packets of the corresponding background flows so as to reserve more bandwidth for burst flows. SDTCP is transparent to the end systems and can accurately decelerate the rate of background flows by leveraging the global view of the network gained via SDN. The experiments demonstrate that our SDTCP can provide high tolerance for burst flows and achieve better flow completion time for short flows. Therefore, SDTCP is an effective and scalable solution for the TCP incast problem.

  20. A New TCP Congestion Control Supporting RTT-Fairness

    NASA Astrophysics Data System (ADS)

    Ogura, Kazumine; Nemoto, Yohei; Su, Zhou; Katto, Jiro

    This paper focuses on RTT-fairness of multiple TCP flows over the Internet, and proposes a new TCP congestion control named “HRF (Hybrid RTT-Fair)-TCP”. Today, it is a serious problem that the flows having smaller RTT utilize more bandwidth than others when multiple flows having different RTT values compete in the same network. This means that a user with longer RTT may not be able to obtain sufficient bandwidth by the current methods. This RTT fairness issue has been discussed in many TCP papers. An example is CR (Constant Rate) algorithm, which achieves RTT-fairness by multiplying the square of RTT value in its window increment phase against TCP-Reno. However, the method halves its windows size same as TCP-Reno when a packet loss is detected. This makes worse its efficiency in certain network cases. On the other hand, recent proposed TCP versions essentially require throughput efficiency and TCP-friendliness with TCP-Reno. Therefore, we try to keep these advantages in our TCP design in addition to RTT-fairness. In this paper, we make intuitive analytical models in which we separate resource utilization processes into two cases: utilization of bottleneck link capacity and that of buffer space at the bottleneck link router. These models take into account three characteristic algorithms (Reno, Constant Rate, Constant Increase) in window increment phase where a sender receives an acknowledgement successfully. Their validity is proved by both simulations and implementations. From these analyses, we propose HRF-TCP which switches two modes according to observed RTT values and achieves RTT fairness. Experiments are carried out to validate the proposed method. Finally, HRF-TCP outperforms conventional methods in RTT-fairness, efficiency and friendliness with TCP-Reno.

  1. Genome-wide analysis of TCP family in tobacco.

    PubMed

    Chen, L; Chen, Y Q; Ding, A M; Chen, H; Xia, F; Wang, W F; Sun, Y H

    2016-05-23

    The TCP family is a transcription factor family, members of which are extensively involved in plant growth and development as well as in signal transduction in the response against many physiological and biochemical stimuli. In the present study, 61 TCP genes were identified in tobacco (Nicotiana tabacum) genome. Bioinformatic methods were employed for predicting and analyzing the gene structure, gene expression, phylogenetic analysis, and conserved domains of TCP proteins in tobacco. The 61 NtTCP genes were divided into three diverse groups, based on the division of TCP genes in tomato and Arabidopsis, and the results of the conserved domain and sequence analyses further confirmed the classification of the NtTCP genes. The expression pattern of NtTCP also demonstrated that majority of these genes play important roles in all the tissues, while some special genes exercise their functions only in specific tissues. In brief, the comprehensive and thorough study of the TCP family in other plants provides sufficient resources for studying the structure and functions of TCPs in tobacco.

  2. ACTS 118x Final Report High-Speed TCP Interoperability Testing

    NASA Technical Reports Server (NTRS)

    Ivancic, William D.; Zernic, Mike; Hoder, Douglas J.; Brooks, David E.; Beering, Dave R.; Welch, Arun

    1999-01-01

    With the recent explosion of the Internet and the enormous business opportunities available to communication system providers, great interest has developed in improving the efficiency of data transfer using the Transmission Control Protocol (TCP) of the Internet Protocol (IP) suite. The satellite system providers are interested in solving TCP efficiency problems associated with long delays and error-prone links. Similarly, the terrestrial community is interested in solving TCP problems over high-bandwidth links. Whereas the wireless community is interested in improving TCP performance over bandwidth constrained, error-prone links. NASA realized that solutions had already been proposed for most of the problems associated with efficient data transfer over large bandwidth-delay links (which include satellite links). The solutions are detailed in various Internet Engineering Task Force (IETF) Request for Comments (RFCs). Unfortunately, most of these solutions had not been tested at high-speed (155+ Mbps). Therefore, the NASA's ACTS experiments program initiated a series of TCP experiments to demonstrate scalability of TCP/IP and determine how far the protocol can be optimized over a 622 Mbps satellite link. These experiments were known as the 118i and 118j experiments. During the 118i and 118j experiments, NASA worked closely with SUN Microsystems and FORE Systems to improve the operating system, TCP stacks. and network interface cards and drivers. We were able to obtain instantaneous data throughput rates of greater than 520 Mbps and average throughput rates of 470 Mbps using TCP over Asynchronous Transfer Mode (ATM) over a 622 Mbps Synchronous Optical Network (SONET) OC12 link. Following the success of these experiments and the successful government/industry collaboration, a new series of experiments. the 118x experiments. were developed.

  3. Genome-wide identification and expression analysis of the ClTCP transcription factors in Citrullus lanatus.

    PubMed

    Shi, Pibiao; Guy, Kateta Malangisha; Wu, Weifang; Fang, Bingsheng; Yang, Jinghua; Zhang, Mingfang; Hu, Zhongyuan

    2016-04-12

    The plant-specific TCP transcription factor family, which is involved in the regulation of cell growth and proliferation, performs diverse functions in multiple aspects of plant growth and development. However, no comprehensive analysis of the TCP family in watermelon (Citrullus lanatus) has been undertaken previously. A total of 27 watermelon TCP encoding genes distributed on nine chromosomes were identified. Phylogenetic analysis clustered the genes into 11 distinct subgroups. Furthermore, phylogenetic and structural analyses distinguished two homology classes within the ClTCP family, designated Class I and Class II. The Class II genes were differentiated into two subclasses, the CIN subclass and the CYC/TB1 subclass. The expression patterns of all members were determined by semi-quantitative PCR. The functions of two ClTCP genes, ClTCP14a and ClTCP15, in regulating plant height were confirmed by ectopic expression in Arabidopsis wild-type and ortholog mutants. This study represents the first genome-wide analysis of the watermelon TCP gene family, which provides valuable information for understanding the classification and functions of the TCP genes in watermelon.

  4. Engineering Vascularized Bone Grafts by Integrating a Biomimetic Periosteum and β-TCP Scaffold

    PubMed Central

    2015-01-01

    Treatment of large bone defects using synthetic scaffolds remain a challenge mainly due to insufficient vascularization. This study is to engineer a vascularized bone graft by integrating a vascularized biomimetic cell-sheet-engineered periosteum (CSEP) and a biodegradable macroporous beta-tricalcium phosphate (β-TCP) scaffold. We first cultured human mesenchymal stem cells (hMSCs) to form cell sheet and human umbilical vascular endothelial cells (HUVECs) were then seeded on the undifferentiated hMSCs sheet to form vascularized cell sheet for mimicking the fibrous layer of native periosteum. A mineralized hMSCs sheet was cultured to mimic the cambium layer of native periosteum. This mineralized hMSCs sheet was first wrapped onto a cylindrical β-TCP scaffold followed by wrapping the vascularized HUVEC/hMSC sheet, thus generating a biomimetic CSEP on the β-TCP scaffold. A nonperiosteum structural cell sheets-covered β-TCP and plain β-TCP were used as controls. In vitro studies indicate that the undifferentiated hMSCs sheet facilitated HUVECs to form rich capillary-like networks. In vivo studies indicate that the biomimetic CSEP enhanced angiogenesis and functional anastomosis between the in vitro preformed human capillary networks and the mouse host vasculature. MicroCT analysis and osteocalcin staining show that the biomimetic CSEP/β-TCP graft formed more bone matrix compared to the other groups. These results suggest that the CSEP that mimics the cellular components and spatial configuration of periosteum plays a critical role in vascularization and osteogenesis. Our studies suggest that a biomimetic periosteum-covered β-TCP graft is a promising approach for bone regeneration. PMID:24858072

  5. Biotype-specific tcpA genes in Vibrio cholerae.

    PubMed

    Iredell, J R; Manning, P A

    1994-08-01

    The tcpA gene, encoding the structural subunit of the toxin-coregulated pilus, has been isolated from a variety of clinical isolates of Vibrio cholerae, and the nucleotide sequence determined. Strict biotype-specific conservation within both the coding and putative regulatory regions was observed, with important differences between the El Tor and classical biotypes. V. cholerae O139 Bengal strains appear to have El Tor-type tcpA genes. Environmental O1 and non-O1 isolates have sequences that bind an El Tor-specific tcpA DNA probe and that are weakly and variably amplified by tcpA-specific polymerase chain reaction primers, under conditions of reduced stringency. The data presented allow the selection of primer pairs to help distinguish between clinical and environmental isolates, and to distinguish El Tor (and Bengal) biotypes from classical biotypes of V. cholerae. While the role of TcpA in cholera vaccine preparations remains unclear, the data strongly suggest that TcpA-containing vaccines directed at O1 strains need include only the two forms of TcpA, and that such vaccines directed at (O139) Bengal strains should include the TcpA of El Tor biotype.

  6. Using the ACR/NEMA standard with TCP/IP and Ethernet

    NASA Astrophysics Data System (ADS)

    Chimiak, William J.; Williams, Rodney C.

    1991-07-01

    There is a need for a consolidated picture archival and communications system (PACS) in hospitals. At the Bowman Gray School of Medicine of Wake Forest University (BGSM), the authors are enhancing the ACR/NEMA Version 2 protocol using UNIX sockets and TCP/IP to greatly improve connectivity. Initially, nuclear medicine studies using gamma cameras are to be sent to PACS. The ACR/NEMA Version 2 protocol provides the functionality of the upper three layers of the open system interconnection (OSI) model in this implementation. The images, imaging equipment information, and patient information are then sent in ACR/NEMA format to a software socket. From there it is handed to the TCP/IP protocol, which provides the transport and network service. TCP/IP, in turn, uses the services of IEEE 802.3 (Ethernet) to complete the connectivity. The advantage of this implementation is threefold: (1) Only one I/O port is consumed by numerous nuclear medicine cameras, instead of a physical port for each camera. (2) Standard protocols are used which maximize interoperability with ACR/NEMA compliant PACSs. (3) The use of sockets allows a migration path to the transport and networking services of OSIs TP4 and connectionless network service as well as the high-performance protocol being considered by the American National Standards Institute (ANSI) and the International Standards Organization (ISO) -- the Xpress Transfer Protocol (XTP). The use of sockets also gives access to ANSI's Fiber Distributed Data Interface (FDDI) as well as other high-speed network standards.

  7. Transcriptome - Scale characterization of salt responsive bean TCP transcription factors.

    PubMed

    İlhan, Emre; Büyük, İlker; İnal, Behcet

    2018-02-05

    TEOSINTE-BRANCHED1/CYCLOIDEA/PCF (TCP) proteins are important regulators of growth and developmental processes including branching, floral organ morphogenesis and leaf growth as well as stress response. This study identified 27 TCP genes of Phaseolus vulgaris (common bean), which were divided into three clusters based on phylogenetic relationship. In addition, this study showed that some of TCP genes such as Pvul-TCP-4 and Pvul-TCP-15 located on chromosomes 3 and 7, Pvul-TCP-7 and Pvul-TCP-20 located on chromosome 7 and 9, were segmentally duplicated. On the other hand, a total of 20 Pvul-TCP genes have predicted to be targeted by microRNAs (miRNA). Most of the miRNA-target genes were Pvul-TCP-1, -11, -13 and -27, which were targeted by 13, 17, 22 and 13 plant miRNAs, respectively. miR319 was one of the highly represented regulatory miRNAs to target TCP transcripts. Promoter region analysis of TCP genes resulted that the GT-1 motif, which was related to salt stress, was found in 14 different Pvul-TCP genes. Expression profiling of 10 Pvul-TCP genes based on RNA-sequencing data further confirmed with quantitative real-time RT-PCR measurements identified that Pvul-TCP genes under salt stress are expressed in a cultivar- and tissue-specific manner. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Evolution and Expression Patterns of TCP Genes in Asparagales

    PubMed Central

    Madrigal, Yesenia; Alzate, Juan F.; Pabón-Mora, Natalia

    2017-01-01

    CYCLOIDEA-like genes are involved in the symmetry gene network, limiting cell proliferation in the dorsal regions of bilateral flowers in core eudicots. CYC-like and closely related TCP genes (acronym for TEOSINTE BRANCHED1, CYCLOIDEA, and PROLIFERATION CELL FACTOR) have been poorly studied in Asparagales, the largest order of monocots that includes both bilateral flowers in Orchidaceae (ca. 25.000 spp) and radially symmetrical flowers in Hypoxidaceae (ca. 200 spp). With the aim of assessing TCP gene evolution in the Asparagales, we isolated TCP-like genes from publicly available databases and our own transcriptomes of Cattleya trianae (Orchidaceae) and Hypoxis decumbens (Hypoxidaceae). Our matrix contains 452 sequences representing the three major clades of TCP genes. Besides the previously identified CYC specific core eudicot duplications, our ML phylogenetic analyses recovered an early CIN-like duplication predating all angiosperms, two CIN-like Asparagales-specific duplications and a duplication prior to the diversification of Orchidoideae and Epidendroideae. In addition, we provide evidence of at least three duplications of PCF-like genes in Asparagales. While CIN-like and PCF-like genes have multiplied in Asparagales, likely enhancing the genetic network for cell proliferation, CYC-like genes remain as single, shorter copies with low expression. Homogeneous expression of CYC-like genes in the labellum as well as the lateral petals suggests little contribution to the bilateral perianth in C. trianae. CIN-like and PCF-like gene expression suggests conserved roles in cell proliferation in leaves, sepals and petals, carpels, ovules and fruits in Asparagales by comparison with previously reported functions in core eudicots and monocots. This is the first large scale analysis of TCP-like genes in Asparagales that will serve as a platform for in-depth functional studies in emerging model monocots. PMID:28144250

  9. Estimating Bottleneck Bandwidth using TCP

    NASA Technical Reports Server (NTRS)

    Allman, Mark

    1998-01-01

    Various issues associated with estimating bottleneck bandwidth using TCP are presented in viewgraph form. Specific topics include: 1) Why TCP is wanted to estimate the bottleneck bandwidth; 2) Setting ssthresh to an appropriate value to reduce loss; 3) Possible packet-pair solutions; and 4) Preliminary results: ACTS and the Internet.

  10. Redox-Dependent Modulation of Anthocyanin Biosynthesis by the TCP Transcription Factor TCP15 during Exposure to High Light Intensity Conditions in Arabidopsis1[OPEN

    PubMed Central

    Viola, Ivana L.; Gonzalez, Daniel H.

    2016-01-01

    TCP proteins integrate a family of transcription factors involved in the regulation of developmental processes and hormone responses. It has been shown that most members of class I, one of the two classes in which the TCP family is divided, contain a conserved Cys that leads to inhibition of DNA binding when oxidized. In this work, we describe that the class-I TCP protein TCP15 inhibits anthocyanin accumulation during exposure of plants to high light intensity by modulating the expression of transcription factors involved in the induction of anthocyanin biosynthesis genes, as suggested by the study of plants that express TCP15 from the 35SCaMV promoter and mutants in TCP15 and the related gene TCP14. In addition, the effect of TCP15 on anthocyanin accumulation is lost after prolonged incubation under high light intensity conditions. We provide evidence that this is due to inactivation of TCP15 by oxidation of Cys-20 of the TCP domain. Thus, redox modulation of TCP15 activity in vivo by high light intensity may serve to adjust anthocyanin accumulation to the duration of exposure to high irradiation conditions. PMID:26574599

  11. Genome-Wide Identification and Characterization of BrrTCP Transcription Factors in Brassica rapa ssp. rapa.

    PubMed

    Du, Jiancan; Hu, Simin; Yu, Qin; Wang, Chongde; Yang, Yunqiang; Sun, Hang; Yang, Yongping; Sun, Xudong

    2017-01-01

    The teosinte branched1/cycloidea/proliferating cell factor (TCP) gene family is a plant-specific transcription factor that participates in the control of plant development by regulating cell proliferation. However, no report is currently available about this gene family in turnips ( Brassica rapa ssp. rapa ). In this study, a genome-wide analysis of TCP genes was performed in turnips. Thirty-nine TCP genes in turnip genome were identified and distributed on 10 chromosomes. Phylogenetic analysis clearly showed that the family was classified as two clades: class I and class II. Gene structure and conserved motif analysis showed that the same clade genes have similar gene structures and conserved motifs. The expression profiles of 39 TCP genes were determined through quantitative real-time PCR. Most CIN-type BrrTCP genes were highly expressed in leaf. The members of CYC/TB1 subclade are highly expressed in flower bud and weakly expressed in root. By contrast, class I clade showed more widespread but less tissue-specific expression patterns. Yeast two-hybrid data show that BrrTCP proteins preferentially formed heterodimers. The function of BrrTCP2 was confirmed through ectopic expression of BrrTCP2 in wild-type and loss-of-function ortholog mutant of Arabidopsis. Overexpression of BrrTCP2 in wild-type Arabidopsis resulted in the diminished leaf size. Overexpression of BrrTCP2 in triple mutants of tcp2/4/10 restored the leaf phenotype of tcp2/4/10 to the phenotype of wild type. The comprehensive analysis of turnip TCP gene family provided the foundation to further study the roles of TCP genes in turnips.

  12. The enzyme toxicity and genotoxicity of chlorpyrifos and its toxic metabolite TCP to zebrafish Danio rerio.

    PubMed

    Wang, Jun; Wang, Jinhua; Zhu, Lusheng; Xie, Hui; Shao, Bo; Hou, Xinxin

    2014-12-01

    Chlorpyrifos is a broad-spectrum organophosphorus insecticide (O,O-diethyl -O-3,5,6-trichloro-2-pyridyl phosphorothioate) that is used in numerous agricultural and urban pest controls. The primary metabolite of chlorpyrifos is 3,5,6-trichloro pyridine-2-phenol (TCP). Because of its strong water solubility and mobility, this harmful metabolite exists in the environment in a large amount. Although TCP has potentially harmful effects on organisms in the environment, few studies have addressed TCP pollution. Therefore, this study was undertaken to investigate the effect of chlorpyrifos and TCP on the microsomal cytochrome P450 content in the liver, on the activity of NADPH-P450 reductase and antioxidative enzymes [catalase (CAT) and superoxide dismutase (SOD)], and on reactive oxygen species (ROS) generation and DNA damage in zebrafish. Male and female zebrafish were separated and exposed to a control solution and three concentrations of chlorpyrifos (0.01, 0.1, 1 mg L(-1)) and TCP (0.01, 0.1, 0.5 mg L(-1)), respectively, sampled after 5, 10, 15, 20 and 25 days. The results indicated that the P450 content and the NADPH-P450 reductase and antioxidative enzyme (CAT and SOD) activities could be induced by chlorpyrifos and TCP. DNA damage of zebrafish was enhanced with increasing chlorpyrifos and TCP concentrations. Meanwhile, chlorpyrifos and TCP induced a significant increase of ROS generation in the zebrafish hepatopancreas. In conclusion, this study proved that chlorpyrifos (0.01-1 mg L(-1)) and TCP (0.01-0.5 mg L(-1)) are both highly toxic to zebrafish.

  13. Identification and expression profiling analysis of TCP family genes involved in growth and development in maize.

    PubMed

    Chai, Wenbo; Jiang, Pengfei; Huang, Guoyu; Jiang, Haiyang; Li, Xiaoyu

    2017-10-01

    The TCP family is a group of plant-specific transcription factors. TCP genes encode proteins harboring bHLH structure, which is implicated in DNA binding and protein-protein interactions and known as the TCP domain. TCP genes play important roles in plant development and have been evolutionarily and functionally elaborated in various plants, however, no overall phylogenetic analysis or expression profiling of TCP genes in Zea mays has been reported. In the present study, a systematic analysis of molecular evolution and functional prediction of TCP family genes in maize ( Z . mays L.) has been conducted. We performed a genome-wide survey of TCP genes in maize, revealing the gene structure, chromosomal location and phylogenetic relationship of family members. Microsynteny between grass species and tissue-specific expression profiles were also investigated. In total, 29 TCP genes were identified in the maize genome, unevenly distributed on the 10 maize chromosomes. Additionally, ZmTCP genes were categorized into nine classes based on phylogeny and purifying selection may largely be responsible for maintaining the functions of maize TCP genes. What's more, microsynteny analysis suggested that TCP genes have been conserved during evolution. Finally, expression analysis revealed that most TCP genes are expressed in the stem and ear, which suggests that ZmTCP genes influence stem and ear growth. This result is consistent with the previous finding that maize TCP genes represses the growth of axillary organs and enables the formation of female inflorescences. Altogether, this study presents a thorough overview of TCP family in maize and provides a new perspective on the evolution of this gene family. The results also indicate that TCP family genes may be involved in development stage in plant growing conditions. Additionally, our results will be useful for further functional analysis of the TCP gene family in maize.

  14. Nano SiO2 and MgO improve the properties of porous β-TCP scaffolds via advanced manufacturing technology.

    PubMed

    Gao, Chengde; Wei, Pingpin; Feng, Pei; Xiao, Tao; Shuai, Cijun; Peng, Shuping

    2015-03-25

    Nano SiO2 and MgO particles were incorporated into β-tricalcium phosphate (β-TCP) scaffolds to improve the mechanical and biological properties. The porous cylindrical β-TCP scaffolds doped with 0.5 wt % SiO2, 1.0 wt % MgO, 0.5 wt % SiO2 + 1.0 wt % MgO were fabricated via selective laser sintering respectively and undoped β-TCP scaffold was also prepared as control. The phase composition and mechanical strength of the scaffolds were evaluated. X-ray diffraction analysis indicated that the phase transformation from β-TCP to α-TCP was inhibited after the addition of MgO. The compressive strength of scaffold was improved from 3.12 ± 0.36 MPa (β-TCP) to 5.74 ± 0.62 MPa (β-TCP/SiO2), 9.02 ± 0.55 MPa (β-TCP/MgO) and 10.43 ± 0.28 MPa (β-TCP/SiO2/MgO), respectively. The weight loss and apatite-forming ability of the scaffolds were evaluated by soaking them in simulated body fluid. The results demonstrated that both SiO2 and MgO dopings slowed down the degradation rate and improved the bioactivity of β-TCP scaffolds. In vitro cell culture studies indicated that SiO2 and MgO dopings facilitated cell attachment and proliferation. Combined addition of SiO2 and MgO were found optimal in enhancing both the mechanical and biological properties of β-TCP scaffold.

  15. Nano SiO2 and MgO Improve the Properties of Porous β-TCP Scaffolds via Advanced Manufacturing Technology

    PubMed Central

    Gao, Chengde; Wei, Pingpin; Feng, Pei; Xiao, Tao; Shuai, Cijun; Peng, Shuping

    2015-01-01

    Nano SiO2 and MgO particles were incorporated into β-tricalcium phosphate (β-TCP) scaffolds to improve the mechanical and biological properties. The porous cylindrical β-TCP scaffolds doped with 0.5 wt % SiO2, 1.0 wt % MgO, 0.5 wt % SiO2 + 1.0 wt % MgO were fabricated via selective laser sintering respectively and undoped β-TCP scaffold was also prepared as control. The phase composition and mechanical strength of the scaffolds were evaluated. X-ray diffraction analysis indicated that the phase transformation from β-TCP to α-TCP was inhibited after the addition of MgO. The compressive strength of scaffold was improved from 3.12 ± 0.36 MPa (β-TCP) to 5.74 ± 0.62 MPa (β-TCP/SiO2), 9.02 ± 0.55 MPa (β-TCP/MgO) and 10.43 ± 0.28 MPa (β-TCP/SiO2/MgO), respectively. The weight loss and apatite-forming ability of the scaffolds were evaluated by soaking them in simulated body fluid. The results demonstrated that both SiO2 and MgO dopings slowed down the degradation rate and improved the bioactivity of β-TCP scaffolds. In vitro cell culture studies indicated that SiO2 and MgO dopings facilitated cell attachment and proliferation. Combined addition of SiO2 and MgO were found optimal in enhancing both the mechanical and biological properties of β-TCP scaffold. PMID:25815597

  16. Arabidopsis Class I and Class II TCP Transcription Factors Regulate Jasmonic Acid Metabolism and Leaf Development Antagonistically1[C][W

    PubMed Central

    Danisman, Selahattin; van der Wal, Froukje; Dhondt, Stijn; Waites, Richard; de Folter, Stefan; Bimbo, Andrea; van Dijk, Aalt DJ; Muino, Jose M.; Cutri, Lucas; Dornelas, Marcelo C.; Angenent, Gerco C.; Immink, Richard G.H.

    2012-01-01

    TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR1 (TCP) transcription factors control developmental processes in plants. The 24 TCP transcription factors encoded in the Arabidopsis (Arabidopsis thaliana) genome are divided into two classes, class I and class II TCPs, which are proposed to act antagonistically. We performed a detailed phenotypic analysis of the class I tcp20 mutant, showing an increase in leaf pavement cell sizes in 10-d-old seedlings. Subsequently, a glucocorticoid receptor induction assay was performed, aiming to identify potential target genes of the TCP20 protein during leaf development. The LIPOXYGENASE2 (LOX2) and class I TCP9 genes were identified as TCP20 targets, and binding of TCP20 to their regulatory sequences could be confirmed by chromatin immunoprecipitation analyses. LOX2 encodes for a jasmonate biosynthesis gene, which is also targeted by class II TCP proteins that are under the control of the microRNA JAGGED AND WAVY (JAW), although in an antagonistic manner. Mutation of TCP9, the second identified TCP20 target, resulted in increased pavement cell sizes during early leaf developmental stages. Analysis of senescence in the single tcp9 and tcp20 mutants and the tcp9tcp20 double mutants showed an earlier onset of this process in comparison with wild-type control plants in the double mutant only. Both the cell size and senescence phenotypes are opposite to the known class II TCP mutant phenotype in JAW plants. Altogether, these results point to an antagonistic function of class I and class II TCP proteins in the control of leaf development via the jasmonate signaling pathway. PMID:22718775

  17. Fabrication of interconnected porous β-tricalcium phosphate (β-TCP) based on a setting reaction of β-TCP granules with HNO3 followed by heat treatment.

    PubMed

    Ishikawa, Kunio; Putri, Tansza Setiana; Tsuchiya, Akira; Tanaka, Keisuke; Tsuru, Kanji

    2018-03-01

    β-Tricalcium phosphate [β-TCP] is the typical bone substitute due to its excellent osteoconductivity and bioresorbability. One of the keys to improve its potential as bone substitute is to introduce porous structure and its regulation. In this study, interconnected porous β-TCP blocks were fabricated through a setting reaction of β-TCP granules and subsequent heat treatment. First, β-TCP granules were mixed with HNO 3 . Upon mixing, β-TCP granules were bridged with dicalcium phosphate dihydrate [DCPD: CaHPO 4 ·2H 2 O] containing Ca(NO 3 ) 2 . Then, the DCPD-bridged β-TCP was heated at 1100°C. During the heating process, DCPD containing Ca(NO 3 ) 2 transformed into β-TCP and bonded with β-TCP granules. As a result, an interconnected porous β-TCP block formed. The diametral tensile strength and porosity of the interconnected porous β-TCP block fabricated from 200-300-μm β-TCP granules and 5 N HNO 3 and then heated at 1,100°C were 1.4 ± 0.2 MPa and 57% ± 2%, respectively. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 797-804, 2018. © 2017 Wiley Periodicals, Inc.

  18. A transport level approach for TCP to support differentiated services

    NASA Astrophysics Data System (ADS)

    Xian, Yong-Ju; Tao, Yang; Xu, Chang-Biao

    2004-04-01

    Recently, there is an increasing interests in providing differentiated services in Internet. However, research efforts have almost exclusively focused on routers by improving their policies of packet scheduling and queue management. There has been much less work on transport level approaches to support differentiated services. The mechanism presented by Chang-Biao Xu, DSAS-TCP and MulTCP are the only pieces of the works in this direction known to the authors. Up to now, there is no paper to discuss the interrelation between these mechanisms. Regarding throughput as TCP criteria to support proportional-differentiated-services (PDS), this paper deeply explores the variants of AIMD(a,b)-based TCP congestion control and their effect on differentiated services, and presents a transport level approach for TCP to support PDS, namely PDS_TCP which can be obtained by introducing weighted factor to a or b of AIMD(a,b)-based TCP congestion control. PDS_TCP also takes into account the influence of slow start for timeout. From the analysis, this paper draws the conclusion that the existing mechanisms are only variants of PDS_TCP. For the example of PDS_TCP, the principles, implementation and simulation results of PDS_a_TCP are discussed in detail. The theory analysis and simulation results show that the proposed mechanism PDS_TCP can be implemented with lower additional overheads and support controlled PDS very well without the loss of flexibility.

  19. Genome-wide identification and characterization of TCP transcription factor genes in upland cotton (Gossypium hirsutum).

    PubMed

    Li, Wen; Li, Deng-Di; Han, Li-Hong; Tao, Miao; Hu, Qian-Qian; Wu, Wen-Ying; Zhang, Jing-Bo; Li, Xue-Bao; Huang, Geng-Qing

    2017-08-31

    TCP proteins are plant-specific transcription factors (TFs), and perform a variety of physiological functions in plant growth and development. In this study, 74 non-redundant TCP genes were identified in upland cotton (Gossypium hirsutum L.) genome. Cotton TCP family can be classified into two classes (class I and class II) that can be further divided into 11 types (groups) based on their motif composition. Quantitative RT-PCR analysis indicated that GhTCPs display different expression patterns in cotton tissues. The majority of these genes are preferentially or specifically expressed in cotton leaves, while some GhTCP genes are highly expressed in initiating fibers and/or elongating fibers of cotton. Yeast two-hybrid results indicated that GhTCPs can interact with each other to form homodimers or heterodimers. In addition, GhTCP14a and GhTCP22 can interact with some transcription factors which are involved in fiber development. These results lay solid foundation for further study on the functions of TCP genes during cotton fiber development.

  20. Vancomycin containing PLLA/β-TCP controls experimental osteomyelitis in vivo.

    PubMed

    Kankilic, Berna; Bilgic, Elif; Korkusuz, Petek; Korkusuz, Feza

    2014-11-19

    Implant-related osteomyelitis (IRO) is recently controlled with local antibiotic delivery systems to overcome conventional therapy disadvantages. In vivo evaluation of such systems is however too little. We asked whether vancomycin (V)-containing poly-l-lactic acid/β-tricalcium phosphate (PLLA/β-TCP) composites control experimental IRO and promote bone healing in vivo. Fifty-six rats were distributed to five groups in this longitudinal controlled study. Experimental IRO was established at tibiae by injecting methicillin-resistant Staphylococcus aureus (MRSA) suspensions with titanium particles in 32 rats. Vancomycin-free PLLA/β-TCP composites were implanted into the normal and infected tibiae, whereas V-PLLA/β-TCP composites and coated (C)-V-PLLA/β-TCP composites were implanted into IRO sites. Sham-operated tibiae established the control group. Radiological and histological scores were quantified with microbiological findings on weeks 1 and 6. IRO is resolved in the CV- and the V-PLLA/β-TCP groups but not in the PLLA/β-TCP group. MRSA was not isolated in the CV- and the V-PLLA/β-TCP groups at all times whereas the bacteria were present in the PLLA/β-TCP group. Radiological signs secondary to infection are improved from 10.9 ± 0.9 to 3.0 ± 0.3 in the V-PLLA/β-TCP group but remained constant in the PLLA/β-TCP group. Histology scores are improved from 24.7 ± 6.5 to 17.6 ± 4.8 and from 27.6 ± 7.9 to 32.4 ± 8.9 in the CV-PLLA/β-TCP and the V-PLLA/β-TCP groups, respectively. New bone was formed in all the PLLA/β-TCP group at weeks 1 and 6. CV- and V-PLLA/β-TCP composites controlled experimental IRO and promoted bone healing. CV- and V-PLLA/β-TCP composites have the potential of controlling experimental IRO and promoting bone healing.

  1. Development and Characterization of Biphasic Hydroxyapatite/β-TCP Cements

    PubMed Central

    Gallinetti, Sara; Canal, Cristina; Ginebra, Maria-Pau; Ferreira, J

    2014-01-01

    Biphasic calcium phosphate bioceramics composed of hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) have relevant properties as synthetic bone grafts, such as tunable resorption, bioactivity, and intrinsic osteoinduction. However, they have some limitations associated to their condition of high-temperature ceramics. In this work self-setting Biphasic Calcium Phosphate Cements (BCPCs) with different HA/β-TCP ratios were obtained from self-setting α-TCP/β-TCP pastes. The strategy used allowed synthesizing BCPCs with modulated composition, compressive strength, and specific surface area. Due to its higher solubility, α-TCP was fully hydrolyzed to a calcium-deficient HA (CDHA), whereas β-TCP remained unreacted and completely embedded in the CDHA matrix. Increasing amounts of the non-reacting β-TCP phase resulted in a linear decrease of the compressive strength, in association to the decreasing amount of precipitated HA crystals, which are responsible for the mechanical consolidation of apatitic cements. Ca2+ release and degradation in acidic medium was similar in all the BCPCs within the timeframe studied, although differences might be expected in longer term studies once β-TCP, the more soluble phase was exposed to the surrounding media. PMID:25866411

  2. Development and Characterization of Biphasic Hydroxyapatite/β-TCP Cements.

    PubMed

    Gallinetti, Sara; Canal, Cristina; Ginebra, Maria-Pau; Ferreira, J

    2014-04-01

    Biphasic calcium phosphate bioceramics composed of hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) have relevant properties as synthetic bone grafts, such as tunable resorption, bioactivity, and intrinsic osteoinduction. However, they have some limitations associated to their condition of high-temperature ceramics. In this work self-setting Biphasic Calcium Phosphate Cements (BCPCs) with different HA/β-TCP ratios were obtained from self-setting α-TCP/β-TCP pastes. The strategy used allowed synthesizing BCPCs with modulated composition, compressive strength, and specific surface area. Due to its higher solubility, α-TCP was fully hydrolyzed to a calcium-deficient HA (CDHA), whereas β-TCP remained unreacted and completely embedded in the CDHA matrix. Increasing amounts of the non-reacting β-TCP phase resulted in a linear decrease of the compressive strength, in association to the decreasing amount of precipitated HA crystals, which are responsible for the mechanical consolidation of apatitic cements. Ca 2+ release and degradation in acidic medium was similar in all the BCPCs within the timeframe studied, although differences might be expected in longer term studies once β-TCP, the more soluble phase was exposed to the surrounding media.

  3. Comprehensive analysis of TCP transcription factors and their expression during cotton (Gossypium arboreum) fiber early development

    PubMed Central

    Ma, Jun; Liu, Fang; Wang, Qinglian; Wang, Kunbo; Jones, Don C.; Zhang, Baohong

    2016-01-01

    TCP proteins are plant-specific transcription factors implicated to perform a variety of physiological functions during plant growth and development. In the current study, we performed for the first time the comprehensive analysis of TCP gene family in a diploid cotton species, Gossypium arboreum, including phylogenetic analysis, chromosome location, gene duplication status, gene structure and conserved motif analysis, as well as expression profiles in fiber at different developmental stages. Our results showed that G. arboreum contains 36 TCP genes, distributing across all of the thirteen chromosomes. GaTCPs within the same subclade of the phylogenetic tree shared similar exon/intron organization and motif composition. In addition, both segmental duplication and whole-genome duplication contributed significantly to the expansion of GaTCPs. Many these TCP transcription factor genes are specifically expressed in cotton fiber during different developmental stages, including cotton fiber initiation and early development. This suggests that TCP genes may play important roles in cotton fiber development. PMID:26857372

  4. Comprehensive analysis of TCP transcription factors and their expression during cotton (Gossypium arboreum) fiber early development.

    PubMed

    Ma, Jun; Liu, Fang; Wang, Qinglian; Wang, Kunbo; Jones, Don C; Zhang, Baohong

    2016-02-09

    TCP proteins are plant-specific transcription factors implicated to perform a variety of physiological functions during plant growth and development. In the current study, we performed for the first time the comprehensive analysis of TCP gene family in a diploid cotton species, Gossypium arboreum, including phylogenetic analysis, chromosome location, gene duplication status, gene structure and conserved motif analysis, as well as expression profiles in fiber at different developmental stages. Our results showed that G. arboreum contains 36 TCP genes, distributing across all of the thirteen chromosomes. GaTCPs within the same subclade of the phylogenetic tree shared similar exon/intron organization and motif composition. In addition, both segmental duplication and whole-genome duplication contributed significantly to the expansion of GaTCPs. Many these TCP transcription factor genes are specifically expressed in cotton fiber during different developmental stages, including cotton fiber initiation and early development. This suggests that TCP genes may play important roles in cotton fiber development.

  5. Fixing Two BSD TCP Bugs

    NASA Technical Reports Server (NTRS)

    Allman, Mark

    1997-01-01

    This note outlines two bugs found in the BSD 4.4 Lite TCP implementation, as well as the implications of these bugs and possible ways to correct them. The first problem encountered in this particular TCP implementation is the use of a 2 segment initial congestion window, rather than the standard 1 segment initial window. The second problem is that the receiver delays ACKs in violation of the delayed ACK rules,

  6. Single-dose local administration of parathyroid hormone (1-34, PTH) with β-tricalcium phosphate/collagen (β-TCP/COL) enhances bone defect healing in ovariectomized rats.

    PubMed

    Tao, Zhou-Shan; Zhou, Wan-Shu; Wu, Xin-Jing; Wang, Lin; Yang, Min; Xie, Jia-Bing; Xu, Zhu-Jun; Ding, Guo-Zheng

    2018-02-01

    Parathyroid hormone (1-34, PTH) combined β-tricalcium phosphate (β-TCP) achieves stable bone regeneration without cell transplantation in previous studies. Recently, with the development of tissue engineering slow release technology, PTH used locally to promote bone defect healing become possible. This study by virtue of collagen with a combination of drugs and has a slow release properties, and investigated bone regeneration by β-TCP/collagen (β-TCP/COL) with the single local administration of PTH. After the creation of a rodent critical-sized femoral metaphyseal bone defect, β-TCP/COL was prepared by mixing sieved granules of β-TCP and atelocollagen for medical use, then β-TCP/COL with dripped PTH solution (1.0 µg) was implanted into the defect of OVX rats until death at 4 and 8 weeks. The defected area in distal femurs of rats was harvested for evaluation by histology, micro-CT, and biomechanics. The results of our study show that single-dose local administration of PTH combined local usage of β-TCP/COL can increase the healing of defects in OVX rats. Furthermore, treatments with single-dose local administration of PTH and β-TCP/COL showed a stronger effect on accelerating the local bone formation than β-TCP/COL used alone. The results from our study demonstrate that combination of single-dose local administration of PTH and β-TCP/COL had an additive effect on local bone formation in osteoporosis rats.

  7. Electrospun Gelatin/β-TCP Composite Nanofibers Enhance Osteogenic Differentiation of BMSCs and In Vivo Bone Formation by Activating Ca (2+) -Sensing Receptor Signaling.

    PubMed

    Zhang, Xuehui; Meng, Song; Huang, Ying; Xu, Mingming; He, Ying; Lin, Hong; Han, Jianmin; Chai, Yuan; Wei, Yan; Deng, Xuliang

    2015-01-01

    Calcium phosphate- (CaP-) based composite scaffolds have been used extensively for the bone regeneration in bone tissue engineering. Previously, we developed a biomimetic composite nanofibrous membrane of gelatin/β-tricalcium phosphate (TCP) and confirmed their biological activity in vitro and bone regeneration in vivo. However, how these composite nanofibers promote the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) is unknown. Here, gelatin/β-TCP composite nanofibers were fabricated by incorporating 20 wt% β-TCP nanoparticles into electrospun gelatin nanofibers. Electron microscopy showed that the composite β-TCP nanofibers had a nonwoven structure with a porous network and a rough surface. Spectral analyses confirmed the presence and chemical stability of the β-TCP and gelatin components. Compared with pure gelatin nanofibers, gelatin/β-TCP composite nanofibers caused increased cell attachment, proliferation, alkaline phosphatase activity, and osteogenic gene expression in rat BMSCs. Interestingly, the expression level of the calcium-sensing receptor (CaSR) was significantly higher on the composite nanofibrous scaffolds than on pure gelatin. For rat calvarial critical sized defects, more extensive osteogenesis and neovascularization occurred in the composite scaffolds group compared with the gelatin group. Thus, gelatin/β-TCP composite scaffolds promote osteogenic differentiation of BMSCs in vitro and bone regeneration in vivo by activating Ca(2+)-sensing receptor signaling.

  8. Identification and Transcript Analysis of the TCP Transcription Factors in the Diploid Woodland Strawberry Fragaria vesca

    PubMed Central

    Wei, Wei; Hu, Yang; Cui, Meng-Yuan; Han, Yong-Tao; Gao, Kuan; Feng, Jia-Yue

    2016-01-01

    Plant-specific TEOSINTE BRANCHED 1, CYCLOIDEA, and PROLIFERATING CELL FACTORS (TCP) transcription factors play versatile functions in multiple processes of plant growth and development. However, no systematic study has been performed in strawberry. In this study, 19 FvTCP genes were identified in the diploid woodland strawberry (Fragaria vesca) accession Heilongjiang-3. Phylogenetic analysis suggested that the FvTCP genes were classified into two main classes, with the second class further divided into two subclasses, which was supported by the exon-intron organizations and the conserved motif structures. Promoter analysis revealed various cis-acting elements related to growth and development, hormone and/or stress responses. We analyzed FvTCP gene transcript accumulation patterns in different tissues and fruit developmental stages. Among them, 12 FvTCP genes exhibited distinct tissue-specific transcript accumulation patterns. Eleven FvTCP genes were down-regulated in different fruit developmental stages, while five FvTCP genes were up-regulated. Transcripts of FvTCP genes also varied with different subcultural propagation periods and were induced by hormone treatments and biotic and abiotic stresses. Subcellular localization analysis showed that six FvTCP-GFP fusion proteins showed distinct localizations in Arabidopsis mesophyll protoplasts. Notably, transient over-expression of FvTCP9 in strawberry fruits dramatically affected the expression of a series of genes implicated in fruit development and ripening. Taken together, the present study may provide the basis for functional studies to reveal the role of this gene family in strawberry growth and development. PMID:28066489

  9. Bone engineering by phosphorylated-pullulan and β-TCP composite.

    PubMed

    Takahata, Tomohiro; Okihara, Takumi; Yoshida, Yasuhiro; Yoshihara, Kumiko; Shiozaki, Yasuyuki; Yoshida, Aki; Yamane, Kentaro; Watanabe, Noriyuki; Yoshimura, Masahide; Nakamura, Mariko; Irie, Masao; Van Meerbeek, Bart; Tanaka, Masato; Ozaki, Toshifumi; Matsukawa, Akihiro

    2015-11-20

    A multifunctional biomaterial with the capacity bond to hard tissues, such as bones and teeth, is a real need for medical and dental applications in tissue engineering and regenerative medicine. Recently, we created phosphorylated-pullulan (PPL), capable of binding to hydroxyapatite in bones and teeth. In the present study, we employed PPL as a novel biocompatible material for bone engineering. First, an in vitro evaluation of the mechanical properties of PPL demonstrated both PPL and PPL/β-TCP composites have higher shear bond strength than materials in current clinical use, including polymethylmethacrylate (PMMA) cement and α-tricalcium phosphate (TCP) cement, Biopex-R. Further, the compressive strength of PPL/β-TCP composite was significantly higher than Biopex-R. Next, in vivo osteoconductivity of PPL/β-TCP composite was investigated in a murine intramedular injection model. Bone formation was observed 5 weeks after injection of PPL/β-TCP composite, which was even more evident at 8 weeks; whereas, no bone formation was detected after injection of PPL alone. We then applied PPL/β-TCP composite to a rabbit ulnar bone defect model and observed bone formation comparable to that induced by Biopex-R. Implantation of PPL/β-TCP composite induced new bone formation at 4 weeks, which was remarkably evident at 8 weeks. In contrast, Biopex-R remained isolated from the surrounding bone at 8 weeks. In a pig vertebral bone defect model, defects treated with PPL/β-TCP composite were almost completely replaced by new bone; whereas, PPL alone failed to induce bone formation. Collectively, our results suggest PPL/β-TCP composite may be useful for bone engineering.

  10. Effects of MgO modified β-TCP nanoparticles on the microstructure and properties of β-TCP/Mg-Zn-Zr composites.

    PubMed

    Zheng, H R; Li, Z; You, C; Liu, D B; Chen, M F

    2017-03-01

    The mechanical properties and corrosion resistance of magnesium alloy composites were improved by the addition of MgO surface modified tricalcium phosphate ceramic nanoparticles (m-β-TCP). Mg-3Zn-0.8Zr composites with unmodified (MZZT) and modified (MZZMT) nanoparticles were produced by high shear mixing technology. Effects of MgO m-β-TCP nanoparticles on the microstructure, mechanical properties, electrochemical corrosion properties and cytocompatibility of Mg-Zn-Zr/β-TCP composites were investigated. After hot extrusion deformation and dynamic recrystallization, the grain size of MZZMT was the half size of MZZT and the distribution of m-β-TCP particles in the matrix was more uniform than β-TCP particles. The yield tensile strength (YTS), ultimate tensile strength (UTS), and corrosion potential (Ecorr) of MZZMT were higher than MZZT; the corrosion current density (I corr ) of MZZMT was lower than MZZT. Cell proliferation of co-cultured MZZMT and MZZT composite samples were roughly the same and the cell number at each time point is higher for MZZMT than for MZZT samples.

  11. Incorporation of RANKL promotes osteoclast formation and osteoclast activity on β-TCP ceramics.

    PubMed

    Choy, John; Albers, Christoph E; Siebenrock, Klaus A; Dolder, Silvia; Hofstetter, Wilhelm; Klenke, Frank M

    2014-12-01

    β-Tricalcium phosphate (β-TCP) ceramics are approved for the repair of osseous defects. In large defects, however, the substitution of the material by authentic bone is inadequate to provide sufficient long-term mechanical stability. We aimed to develop composites of β-TCP ceramics and receptor activator of nuclear factor κ-B ligand (RANKL) to enhance the formation of osteoclasts and promote cell mediated calcium phosphate resorption. RANKL was adsorbed superficially onto β-TCP ceramics or incorporated into a crystalline layer of calcium phosphate by the use of a co-precipitation technique. Murine osteoclast precursors were seeded onto the ceramics. After 15 days, the formation of osteoclasts was quantified cytologically and colorimetrically with tartrate-resistant acidic phosphatase (TRAP) staining and TRAP activity measurements, respectively. Additionally, the expression of transcripts encoding the osteoclast gene products cathepsin K, calcitonin receptor, and of the sodium/hydrogen exchanger NHA2 were quantified by real-time PCR. The activity of newly formed osteoclasts was evaluated by means of a calcium phosphate resorption assay. Superficially adsorbed RANKL did not induce the formation of osteoclasts on β-TCP ceramics. When co-precipitated onto β-TCP ceramics RANKL supported the formation of mature osteoclasts. The development of osteoclast lineage cells was further confirmed by the increased expression of cathepsin K, calcitonin receptor, and NHA2. Incorporated RANKL stimulated the cells to resorb crystalline calcium phosphate. Our in vitro study shows that RANKL incorporated into β-TCP ceramics induces the formation of active, resorbing osteoclasts on the material surface. Once formed, osteoclasts mediate the release of RANKL thereby perpetuating their differentiation and activation. In vivo, the stimulation of osteoclast-mediated resorption may contribute to a coordinated sequence of material resorption and bone formation. Further in vivo studies

  12. Global Connections for Lasting Impressions: Experiential Learning about TCP

    NASA Astrophysics Data System (ADS)

    Allison, Colin; Miller, Alan; Oliver, Iain; Sturgeon, Thomas

    “Tell me and I forget, Show me and I remember, Involve me and I understand”. This paper discusses the motivation for, and design of, a learning resource which allows students to explore the Transmission Control Protocol (TCP). TCP is responsible for transporting over 80% of the traffic on the Internet - all web and e-mail for example - and in addition is the primary means of achieving Internet congestion control. TCP is therefore core to modern life. It is a protocol under constant study with a view to evolution, and it is incumbent on all ICT curricula to provide education at appropriate levels about its dynamics, strengths and weaknesses. There are no shortages of good textbooks which provide information on TCP, but these are no substitute for experiential learning in order to provide a lasting understanding. The TCP Live learning resource allows students to explore the behavior of TCP on the global Internet, and see the wide variety of conditions that the protocol has to cope with, thereby extending their viewpoint outwith the limited scope of their own institutional firewalls.

  13. Compact Modbus TCP/IP protocol for data acquisition systems based on limited hardware resources

    NASA Astrophysics Data System (ADS)

    Bai, Q.; Jin, B.; Wang, D.; Wang, Y.; Liu, X.

    2018-04-01

    The Modbus TCP/IP has been a standard industry communication protocol and widely utilized for establishing sensor-cloud platforms on the Internet. However, numerous existing data acquisition systems built on traditional single-chip microcontrollers without sufficient resources cannot support it, because the complete Modbus TCP/IP protocol always works dependent on a full operating system which occupies abundant hardware resources. Hence, a compact Modbus TCP/IP protocol is proposed in this work to make it run efficiently and stably even on a resource-limited hardware platform. Firstly, the Modbus TCP/IP protocol stack is analyzed and the refined protocol suite is rebuilt by streamlining the typical TCP/IP suite. Then, specific implementation of every hierarchical layer is respectively presented in detail according to the protocol structure. Besides, the compact protocol is implemented in a traditional microprocessor to validate the feasibility of the scheme. Finally, the performance of the proposed scenario is assessed. The experimental results demonstrate that message packets match the frame format of Modbus TCP/IP protocol and the average bandwidth reaches to 1.15 Mbps. The compact protocol operates stably even based on a traditional microcontroller with only 4-kB RAM and 12-MHz system clock, and no communication congestion or frequent packet loss occurs.

  14. Structural and degradation characteristics of an innovative porous PLGA/TCP scaffold incorporated with bioactive molecular icaritin.

    PubMed

    Xie, Xin-Hui; Wang, Xin-Luan; Zhang, Ge; He, Yi-Xin; Wang, Xiao-Hong; Liu, Zhong; He, Kai; Peng, Jiang; Leng, Yang; Qin, Ling

    2010-10-01

    and ingrowth of newly regenerated tissues in vivo. The controlled release of icaritin from the composite scaffold reached about 70% of the incorporated icaritin into the degradation medium after 12 weeks. The above findings suggested that the structural and degradation properties of the porous composite PLGA/TCP/icaritin scaffold were dependent on icaritin concentrations. This innovative composite porous scaffold material developed in the present study may be used as a good scaffold material for enhancing bone repair, especially at high concentrations of icaritin. In vivo confirmation is, however, needed to substantiate our in vitro findings.

  15. Transcription factor AtTCP14 regulates embryonic growth potential during seed germination in Arabidopsis thaliana.

    PubMed

    Tatematsu, Kiyoshi; Nakabayashi, Kazumi; Kamiya, Yuji; Nambara, Eiji

    2008-01-01

    To understand the molecular mechanisms underlying regulation of seed germination, we searched enriched cis elements in the upstream regions of Arabidopsis genes whose transcript levels increased during seed germination. Using available published microarray data, we found that two cis elements, Up1 or Up2, which regulate outgrowth of Arabidopsis axillary shoots, were significantly over-represented. Classification of Up1- and Up2-containing genes by gene ontology revealed that protein synthesis-related genes, especially ribosomal protein genes, were highly over-represented. Expression analysis using a reporter gene driven by a synthetic promoter regulated by these elements showed that the Up1 is necessary and sufficient for germination-associated gene induction, whereas Up2 acts as an enhancer of Up1. Up1-mediated gene expression was suppressed by treatments that blocked germination. Up1 is almost identical to the site II motif, which is the predicted target of TCP transcription factors. Of 24 AtTCP genes, AtTCP14, which showed the highest transcript level just prior to germination, was functionally characterized to test its involvement in the regulation of seed germination. Transposon-tagged lines for AtTCP14 showed delayed germination. In addition, germination of attcp14 mutants exhibited hypersensitivity to exogenously applied abscisic acid and paclobutrazol, an inhibitor of gibberellin biosynthesis. AtTCP14 was predominantly expressed in the vascular tissues of the embryo, and affected gene expression in radicles in a non-cell-autonomous manner. Taken together, these results indicate that AtTCP14 regulates the activation of embryonic growth potential in Arabidopsis seeds.

  16. Effects of ß-TCP scaffolds on neurogenic and osteogenic differentiation of human embryonic stem cells.

    PubMed

    Arpornmaeklong, Premjit; Pressler, Michael J

    2018-01-01

    Extracellular matrix (ECM) and adhesion molecules play crucial roles in regulating growth and differentiation of stem cells. The current study aimed to investigate the effects of beta-tricalcium phosphate (ß-TCP) scaffolds on differentiation and expression of ECM and adhesion molecules of human embryonic stem cells (hESCs). Undifferentiated hESCs were seeded on ß-TCP scaffolds and cell culture plates and cultured in growth and osteogenic medium for 21 days. Scanning electron microscopy (SEM) displayed adhesion and growth of hESCs on the porous ß-TCP scaffolds. Histological analysis, immunohistochemical staining and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) demonstrated that the scaffolds supported growth and differentiation of hESCs. Expression levels of neural crest related genes (AP2a, FoxD3, HNK1, P75, Sox1, Sox10) and osteoblast-related genes (Runx2, SPP1 and BGLA) on the scaffolds in osteogenic medium were significantly higher than on the scaffolds in growth and cell culture plates in osteogenic medium, respectively (p<0.05). Polymerase chain reaction array experiments demonstrated increased expression of ECM and adhesion molecule-related genes on the scaffolds. In conclusion, osteoconductive scaffolds such as ß-TCP scaffolds promoted differentiation of hESCs, particularly expression of genes related to neural crest stem cell and osteoblastic differentiations. Beta-TCP scaffolds could be an alternative cell culture substrate for neural crest and osteogenic differentiation of hESCs. Optimization of culture medium may be necessary to enhance lineage restriction of hESCs on the ß-TCP scaffolds. Copyright © 2017 Elsevier GmbH. All rights reserved.

  17. The class I protein AtTCP15 modulates plant development through a pathway that overlaps with the one affected by CIN-like TCP proteins.

    PubMed

    Uberti-Manassero, Nora G; Lucero, Leandro E; Viola, Ivana L; Vegetti, Abelardo C; Gonzalez, Daniel H

    2012-01-01

    The function of the class I TCP transcription factor TCP15 from Arabidopsis thaliana has been studied through the analysis of plants that express a fusion of this protein to the EAR repressor domain. Constitutive expression of TCP15-EAR produces growth arrest at the seedling stage, before leaf emergence. Expression of the repressor fusion from the AtTCP15 promoter produces small plants with leaves whose margins progressively curve upwards, starting from the basal part of the lamina. Leaves contain smaller and less differentiated cells, both on the adaxial and abaxial sides. The abaxial domain is relatively enlarged, with disorganized cells separated by empty spaces. TCP15-EAR also affects the growth of leaf petioles, flower pedicels, and anther filaments. Flowers show reduced elongation of the three outer whorls and altered gynoecia with irregular carpel surfaces and enlarged repla. Ectopic stigma-like structures develop from medial and basal parts of the replum. TCP15-EAR produces an increase in expression of the boundary-specific genes LOB, CUC1, and CUC2. Changes in CUC1 and CUC2 expression can be explained by the existence of lower levels of miR164 in leaves and the repression of IAA3/SHY2 and the SAUR-like gene At1g29460 in leaves and flowers. TCP15 binds to the promoter regions of IAA3/SHY2 and At1g29460, suggesting that these genes may be direct targets of the transcription factor. The results indicate that TCP15 regulates the expression of boundary-specific genes through a pathway that affects auxin homeostasis and partially overlaps with the one modulated by class II CIN-like TCP proteins.

  18. Effects of concomitant use of fibroblast growth factor (FGF)-2 with beta-tricalcium phosphate ({beta}-TCP) on the beagle dog 1-wall periodontal defect model

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Anzai, Jun, E-mail: anzai_jun@kaken.co.jp; Department of Periodontology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871; Kitamura, Masahiro, E-mail: kitamura@dent.osaka-u.ac.jp

    Research highlights: {yields} Concomitant use of FGF-2 and {beta}-TCP (an osteo-conductive scaffold) significantly promotes periodontal regeneration in the severe periodontitis model (1-wall defect model) of beagle dog. {yields} FGF-2 enhanced new bone formation via {beta}-TCP at the defects. {yields} In particular, FGF-2 dramatically regenerated new periodontal ligament and cementum formations at the defects, that is one of the most important healing outcomes during the process of periodontal regeneration. {yields} Epithelial downgrowth (undesirable wound healing) was decreased by administration of FGF-2. {yields} This manuscript indicates for the first time that concomitant use of FGF-2 and {beta}-TCP is efficacious in regenerating periodontalmore » tissue following severe destruction of the tissue by progression of periodontitis. -- Abstract: The effects of concomitant use of fibroblast growth factor-2 (FGF-2) and beta-tricalcium phosphate ({beta}-TCP) on periodontal regeneration were investigated in the beagle dog 1-wall periodontal defect model. One-wall periodontal defects were created in the mesial portion of both sides of the mandibular first molars, and 0.3% FGF-2 plus {beta}-TCP or {beta}-TCP alone was administered. Radiographic evaluation was performed at 0, 3, and 6 weeks. At 6 weeks, the periodontium with the defect site was removed and histologically analyzed. Radiographic findings showed that co-administration of FGF-2 significantly increased bone mineral contents of the defect sites compared with {beta}-TCP alone. Histologic analysis revealed that the length of the regenerated periodontal ligament, the cementum, distance to the junctional epithelium, new bone height, and area of newly formed bone were significantly increased in the FGF-2 group. No abnormal inflammatory response or ankylosis was observed in either group. These findings indicate the efficacy of concomitant use of FGF-2 and {beta}-TCP as an osteoconductive material for periodontal

  19. Response of human bone marrow-derived MSCs on triphasic Ca-P substrate with various HA/TCP ratio.

    PubMed

    Bajpai, Indu; Kim, Duk Yeon; Kyong-Jin, Jung; Song, In-Hwan; Kim, Sukyoung

    2017-01-01

    Calcium phosphates (Ca-P) are used commonly as artificial bone substitutes to control the biodegradation rate of an implant in the body fluid. This study examined the in vitro proliferation of human bone marrow-derived mesenchymal stem cells (hBMSCs) on triphasic Ca-P samples. For this aspect, hydroxyapatite (HA), dicalcium phosphate dehydrate (DCPD), and calcium hydroxide (Ca(OH) 2 ) were mixed at various ratios, cold compacted, and sintered at 1250°C in air. X-ray diffraction showed that the β-tricalcium phosphate (TCP) to α-TCP phase transformation increased with increasing DCPD/HA ratio. The micro-hardness deceased with increasing TCP content, whereas the mean grain size and porosity increased with increasing TCP concentration. To evaluate the in vitro degree of adhesion and proliferation on the HA/TCP samples, human BMSCs were incubated on the HA/TCP samples and analyzed by a cells proliferation assay, expression of the extracellular matrix (ECM) genes, such as α-smooth muscle actin (α-SMA) and fibronectin (FN), and FITC-phalloidin fluorescent staining. In terms of the interactions of human BMSCs with the triphasic Ca-P samples, H50T50 (Ca/P = 1.59) markedly enhanced cell spreading, proliferation, FN, and α-SMA compared with H100T0 (Ca/P = 1.67). Interestingly, these results show that among the five HA/TCP samples, H50T50 is the optimal Ca-P composition for in vitro cell proliferation. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 72-80, 2017. © 2015 Wiley Periodicals, Inc.

  20. Evaluation of TcpF-A2-CTB Chimera and Evidence of Additive Protective Efficacy of Immunizing with TcpF and CTB in the Suckling Mouse Model of Cholera

    PubMed Central

    Price, Gregory A.; Holmes, Randall K.

    2012-01-01

    The secreted colonization factor, TcpF, which is produced by Vibrio cholerae 01 and 0139, has generated interest as a potential protective antigen in the development of a subunit vaccine against cholera. This study evaluated immunogenicity/protective efficacy of a TcpF holotoxin-like chimera (TcpF-A2-CTB) following intraperitoneal immunization compared to TcpF alone, a TcpF+CTB mixture, or CTB alone. Immunization with the TcpF-A2-CTB chimera elicited significantly greater amounts of anti-TcpF IgG than immunization with the other antigens (P<0.05). Protective efficacy was measured using 6-day-old pups reared from immunized dams and orogastrically challenged with a lethal dose of El Tor V. cholerae 01 Inaba strain N16961. Protection from death, and weight loss analysis at 24 and 48 hours post-infection demonstrated that immunization with TcpF alone was poorly protective. However, immunization with TcpF+CTB was highly protective and showed a trend toward greater protection than immunization with CTB alone (82% vs 64% survival). Immunization with the TcpF-A2-CTB chimera demonstrated less protection (50% survival) than immunization with the TcpF+CTB mixture. The TcpF-A2-CTB chimera used for this study contained the heterologous classical CTB variant whereas the El Tor CTB variant (expressed by the challenge strain) was used in the other immunization groups. For all immunization groups that received CTB, quantitative ELISA data demonstrated that the amounts of serum IgG directed against the homologous immunizing CTB antigen was statistically greater than the amount to the heterologous CTB antigen (P≤0.003). This finding provides a likely explanation for the poorer protection observed following immunization with the TcpF-A2-CTB chimera and the relatively high level of protection seen after immunization with homologous CTB alone. Though immunization with TcpF alone provided no protection, the additive protective effect when TcpF was combined with CTB demonstrates its

  1. Role of UV photolysis in accelerating the biodegradation of 2,4,6-TCP.

    PubMed

    Wang, Wenbing; Kirumba, George; Zhang, Yongming; Wu, Yanqing; Rittmann, Bruce E

    2015-09-18

    2,4,6-TCP, a kind of chlorinated aromatic and aliphatic compound, is difficult to be biodegraded by ordinary microorganisms. UV photolysis and biodegradation of 2,4,6-TCP by Bacillus amyloliquefaciens intimate coupling is a potential means to accelerate its biotransformation. The initial steps of 2,4,6-TCP biodegradation involve mono-oxygenation reactions that have molecular oxygen and an intracellular electron carrier as cosubstrates. It was demonstrated that B. amyloliquefaciens has the 2,4,6-TCP monooxygenase gene tcpA which could encode 2,4,6-TCP monooxygenase (TCP-MO). TCP-MO would catalytically decompose 2,4,6-TCP into 2,6-DCHQ. We employed an internal loop photolytic biofilm reactor for 2,4,6-TCP degradation. Sequentially coupled photolysis and biodegradation experimental results suggested that 2,4,6-TCP removal rate in P + B (TCP(UV) + phenol) protocol was higher by 77 and 103 % when compared to B (TCP + phenol) and B (TCP-only) protocols respectively. The corresponding loss rate coefficient (k) values were 0.069, 0.039, 0.034 mg/L·min -1 respectively. This is because UV photolysis converted 2,4,6-TCP into its intermediates: 2,4-dichlorophenol (2,4-DCP), 4-monochlorophenol (4-MCP), phenol, 2,6-dichloro-p-hydroquinone (2,6-DCHQ), with all displaying less inhibition to bacterial action. In addition, phenol was the crucial UV-photolysis product from 2,4,6-TCP, its catabolic oxidation generating internal electron carriers that may accelerate the initial steps of 2,4,6-TCP biodegradation. Intimately coupled photolysis and biodegradation experimental results suggested that 2,4,6-TCP removal rate in P&B (TCP + phenol) protocol was higher by 166 and 681 % when compared to P&B (TCP-only) and P + B protocols respectively. The corresponding loss rate coefficient (k) values were 0.539, 0.203, 0.069 mg/L·min -1 respectively. It provided sufficient evidence to demonstrate that intimately coupled photolysis and biodegradation accelerated 2,4,6-TCP removal

  2. The Tcp conjugation system of Clostridium perfringens.

    PubMed

    Wisniewski, Jessica A; Rood, Julian I

    2017-05-01

    The Gram-positive pathogen Clostridium perfringens possesses a family of large conjugative plasmids that is typified by the tetracycline resistance plasmid pCW3. Since these plasmids may carry antibiotic resistance genes or genes encoding extracellular or sporulation-associated toxins, the conjugative transfer of these plasmids appears to be important for the epidemiology of C. perfringens-mediated diseases. Sequence analysis of members of this plasmid family identified a highly conserved 35kb region that encodes proteins with various functions, including plasmid replication and partitioning. The tcp conjugation locus also was identified in this region, initially based on low-level amino acid sequence identity to conjugation proteins from the integrative conjugative element Tn916. Genetic studies confirmed that the tcp locus is required for conjugative transfer and combined with biochemical and structural analyses have led to the development of a functional model of the Tcp conjugation apparatus. This review summarises our current understanding of the Tcp conjugation system, which is now one of the best-characterized conjugation systems in Gram-positive bacteria. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Nitrate foraging by Arabidopsis roots is mediated by the transcription factor TCP20 through the systemic signaling pathway

    PubMed Central

    Guan, Peizhu; Wang, Rongchen; Nacry, Philippe; Breton, Ghislain; Kay, Steve A.; Pruneda-Paz, Jose L.; Davani, Ariea; Crawford, Nigel M.

    2014-01-01

    To compete for nutrients in diverse soil microenvironments, plants proliferate lateral roots preferentially in nutrient-rich zones. For nitrate, root foraging involves local and systemic signaling; however, little is known about the genes that function in the systemic signaling pathway. By using nitrate enhancer DNA to screen a library of Arabidopsis transcription factors in the yeast one-hybrid system, the transcription factor gene TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR1-20 (TCP20) was identified. TCP20, which belongs to an ancient, plant-specific gene family that regulates shoot, flower, and embryo development, was implicated in nitrate signaling by its ability to bind DNA in more than 100 nitrate-regulated genes. Analysis of insertion mutants of TCP20 showed that they had normal primary and lateral root growth on homogenous nitrate media but were impaired in preferential lateral root growth (root foraging) on heterogeneous media in split-root plates. Inhibition of preferential lateral root growth was still evident in the mutants even when ammonium was uniformly present in the media, indicating that the TCP20 response was to nitrate. Comparison of tcp20 mutants with those of nlp7 mutants, which are defective in local control of root growth but not in the root-foraging response, indicated that TCP20 function is independent of and distinct from NLP7 function. Further analysis showed that tcp20 mutants lack systemic control of root growth regardless of the local nitrate concentrations. These results indicate that TCP20 plays a key role in the systemic signaling pathway that directs nitrate foraging by Arabidopsis roots. PMID:25288754

  4. Clinical Relevance of Baseline TCP in Transcatheter Aortic Valve Replacement.

    PubMed

    Sannino, Anna; Stoler, Robert C; Hebeler, Robert F; Szerlip, Molly; Mack, Michael J; Grayburn, Paul A

    2017-10-01

    To investigate the influence of baseline thrombocytopenia (TCP) on short-term and long-term outcomes after transcatheter aortic valve replacement (TAVR). A total of 732 consecutive patients with severe, symptomatic aortic stenosis undergoing TAVR from January 2012 to December 2015 were included. Primary outcomes of interest were the relationship of baseline TCP with 30-day and 1-year all-cause mortality. Secondary outcomes of interest were procedural complications and in-hospital mortality in the same subgroups. The prevalence of TCP (defined as platelet count <150 × 109/L) at baseline was 21.9%, of whom 4.0% had moderate/severe TCP (defined as platelet count <100 × 109/L). Compared to no or mild TCP, moderate/severe TCP at baseline was associated with a significantly higher 30-day mortality (23.3% vs 2.3% and 3.1%, respectively; P<.001) and 1-year mortality (40.0% vs 8.3% and 13.4%, respectively; P<.001). In Cox regression analysis, moderate/severe baseline TCP was an independent predictor of 30-day and 1-year mortality (hazard ratio [HR], 13.18; 95% confidence interval [CI], 4.49-38.64; P<.001 and HR, 5.90; 95% CI, 2.68-13.02; P<.001, respectively). In conclusion, baseline TCP is a strong predictor of mortality in TAVR patients, possibly identifying a specific subgroup of frail patients; therefore, it should be taken into account when addressing TAVR risk.

  5. Human Urine Derived Stem Cells in Combination with β-TCP Can Be Applied for Bone Regeneration.

    PubMed

    Guan, Junjie; Zhang, Jieyuan; Li, Haiyan; Zhu, Zhenzhong; Guo, Shangchun; Niu, Xin; Wang, Yang; Zhang, Changqing

    2015-01-01

    Bone tissue engineering requires highly proliferative stem cells that are easy to isolate. Human urine stem cells (USCs) are abundant and can be easily harvested without using an invasive procedure. In addition, in our previous studies, USCs have been proved to be able to differentiate into osteoblasts, chondrocytes, and adipocytes. Therefore, USCs may have great potential and advantages to be applied as a cell source for tissue engineering. However, there are no published studies that describe the interactions between USCs and biomaterials and applications of USCs for bone tissue engineering. Therefore, the objective of the present study was to evaluate the interactions between USCs with a typical bone tissue engineering scaffold, beta-Tricalcium Phosphate (β-TCP), and to determine whether the USCs seeded onto β-TCP scaffold can promote bone regeneration in a segmental femoral defect of rats. Primary USCs were isolated from urine and seeded on β-TCP scaffolds. Results showed that USCs remained viable and proliferated within β-TCP. The osteogenic differentiation of USCs within the scaffolds was demonstrated by increased alkaline phosphatase activity and calcium content. Furthermore, β-TCP with adherent USCs (USCs/β-TCP) were implanted in a 6-mm critical size femoral defect of rats for 12 weeks. Bone regeneration was determined using X-ray, micro-CT, and histologic analyses. Results further demonstrated that USCs in the scaffolds could enhance new bone formation, which spanned bone defects in 5 out of 11 rats while β-TCP scaffold alone induced modest bone formation. The current study indicated that the USCs can be used as a cell source for bone tissue engineering as they are compatible with bone tissue engineering scaffolds and can stimulate the regeneration of bone in a critical size bone defect.

  6. TCP three-way handshake: linking developmental processes with plant immunity.

    PubMed

    Lopez, Jessica A; Sun, Yali; Blair, Peter B; Mukhtar, M Shahid

    2015-04-01

    The TCP gene family encodes plant-specific transcription factors involved in growth and development. Equally important are the interactions between TCP factors and other pathways extending far beyond development, as they have been found to regulate a variety of hormonal pathways and signaling cascades. Recent advances reveal that TCP factors are targets of pathogenic effectors and are likely to play a vital role in plant immunity. Our focus is on reviewing the involvement of TCP in known pathways and shedding light on other linkages in the nexus of plant immunity centered around TCP factors with an emphasis on the convergence of effectors, interconnected hormonal networks, utility of the circadian clock, and the potential mechanisms by which pathogen defense may occur. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Organization of tcp, acf, and toxT genes within a ToxT-dependent operon.

    PubMed

    Brown, R C; Taylor, R K

    1995-05-01

    The toxin coregulated pilus (TCP) is required for Vibrio cholerae to colonize the human intestine. The expression of the pilin gene, tcpA, is dependent upon ToxR and upon ToxT. The toxT gene was recently mapped within the TCP biogenesis gene cluster and shown to be capable of activating a tcpA::TnphoA fusion when cloned in Escherichia coli. In this study, we determined that ToxR/ToxT activation occurs at the level of tcpA transcription. ToxT expressed in E. coli could activate a tcp operon fusion, while ToxR, ToxR with ToxS, or a ToxR-PhoA fusion failed to activate the tcp operon fusion and we could not demonstrate binding of a ToxR extract to the tcpA promoter region in DNA mobility-shift assays. The start site for the regulated promoter was shown by primer extension to lie 75 bp upstream of the first codon of tcpA. An 800-base tcpA message was identified, by Northern analysis, that correlates by size to the distance between the transcriptional start and a hairpin-loop sequence between tcpA and tcpB. The more-sensitive assay of RNase protection analysis demonstrated that a regulated transcript probably extends through the rest of the downstream tcp genes, including toxT and the adjacent accessory colonization factor (acf) genes. An in-frame tcpA deletion, but not a polar tcpA::TnphoA fusion, could be complemented for pilus surface expression by providing tcpA in trans. This evidence suggests that the tcp genes, including toxT, are organized in an operon directly activated by ToxT in a ToxR-dependent manner. Most of the toxT expression under induced conditions requires transcription of the tcpA promoter. Further investigation of how tcp::TnphoA insertions that are polar on toxT expression retain regulation showed that a low basal level of toxT expression is present in toxR and tcp::TnphoA strains. Overall, these observations support the ToxR/ToxT cascade of regulation for tcp. Once induced, toxT expression becomes autoregulatory via the tcp promoter, linking tcp

  8. Fabrication of individual alginate-TCP scaffolds for bone tissue engineering by means of powder printing.

    PubMed

    Castilho, Miguel; Rodrigues, Jorge; Pires, Inês; Gouveia, Barbara; Pereira, Manuel; Moseke, Claus; Groll, Jürgen; Ewald, Andrea; Vorndran, Elke

    2015-01-06

    The development of polymer-calcium phosphate composite scaffolds with tailored architectures and properties has great potential for bone regeneration. Herein, we aimed to improve the functional performance of brittle ceramic scaffolds by developing a promising biopolymer-ceramic network. For this purpose, two strategies, namely, direct printing of a powder composition consisting of a 60:40 mixture of α/β-tricalcium phosphate (TCP) powder and alginate powder or vacuum infiltration of printed TCP scaffolds with an alginate solution, were tracked. Results of structural characterization revealed that the scaffolds printed with 2.5 wt% alginate-modified TCP powders presented a uniformly distributed and interfusing alginate TCP network. Mechanical results indicated a significant increase in strength, energy to failure and reliability of powder-modified scaffolds with an alginate content in the educts of 2.5 wt% when compared to pure TCP, as well as to TCP scaffolds containing 5 wt% or 7.5 wt% in the educts, in both dry and wet states. Culture of human osteoblast cells on these scaffolds also demonstrated a great improvement of cell proliferation and cell viability. While in the case of powder-mixed alginate TCP scaffolds, isolated alginate gels were formed between the calcium phosphate crystals, the vacuum-infiltration strategy resulted in the covering of the surface and internal pores of the TCP scaffold with a thin alginate film. Furthermore, the prediction of the scaffolds' critical fracture conditions under more complex stress states by the applied Mohr fracture criterion confirmed the potential of the powder-modified scaffolds with 2.5 wt% alginate in the educts as structural biomaterial for bone tissue engineering.

  9. Controlled release of NELL-1 protein from chitosan/hydroxyapatite-modified TCP particles.

    PubMed

    Zhang, Yulong; Dong, Rui; Park, Yujin; Bohner, Marc; Zhang, Xinli; Ting, Kang; Soo, Chia; Wu, Benjamin M

    2016-09-10

    NEL-like molecule-1 (NELL-1) is a novel osteogenic protein that showing high specificity to osteochondral cells. It was widely used in bone regeneration research by loading onto carriers such as tricalcium phosphate (TCP) particles. However, there has been little research on protein controlled release from this material and its potential application. In this study, TCP was first modified with a hydroxyapatite coating followed by a chitosan coating to prepare chitosan/hydroxyapatite-coated TCP particles (Chi/HA-TCP). The preparation was characterized by SEM, EDX, FTIR, XRD, FM and Zeta potential measurements. The NELL-1 loaded Chi/HA-TCP particles and the release kinetics were investigated in vitro. It was observed that the Chi/HA-TCP particles prepared with the 0.3% (wt/wt) chitosan solution were able to successfully control the release of NELL-1 and maintain a slow, steady release for up to 28 days. Furthermore, more than 78% of the loaded protein's bioactivity was preserved in Chi/HA-TCP particles over the period of the investigation, which was significantly higher than that of the protein released from hydroxyapatite coated TCP (HA-TCP) particles. Collectively, this study suggests that the osteogenic protein NELL-1 showed a sustained release pattern after being encapsulated into the modified Chi/HA-TCP particles, and the NELL-1 integrated composite of Chi/HA-TCP showed a potential to function as a protein delivery carrier and as an improved bone matrix for use in bone regeneration research. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Analysis of Malicious Traffic in Modbus/TCP Communications

    NASA Astrophysics Data System (ADS)

    Kobayashi, Tiago H.; Batista, Aguinaldo B.; Medeiros, João Paulo S.; Filho, José Macedo F.; Brito, Agostinho M.; Pires, Paulo S. Motta

    This paper presents the results of our analysis about the influence of Information Technology (IT) malicious traffic on an IP-based automation environment. We utilized a traffic generator, called MACE (Malicious trAffic Composition Environment), to inject malicious traffic in a Modbus/TCP communication system and a sniffer to capture and analyze network traffic. The realized tests show that malicious traffic represents a serious risk to critical information infrastructures. We show that this kind of traffic can increase latency of Modbus/TCP communication and that, in some cases, can put Modbus/TCP devices out of communication.

  11. Combination of BMP-2-releasing gelatin/β-TCP sponges with autologous bone marrow for bone regeneration of X-ray-irradiated rabbit ulnar defects.

    PubMed

    Yamamoto, Masaya; Hokugo, Akishige; Takahashi, Yoshitake; Nakano, Takayoshi; Hiraoka, Masahiro; Tabata, Yasuhiko

    2015-07-01

    The objective of this study is to evaluate the feasibility of gelatin sponges incorporating β-tricalcium phosphate (β-TCP) granules (gelatin/β-TCP sponges) to enhance bone regeneration at a segmental ulnar defect of rabbits with X-ray irradiation. After X-ray irradiation of the ulnar bone, segmental critical-sized defects of 20-mm length were created, and bone morphogenetic protein-2 (BMP-2)-releasing gelatin/β-TCP sponges with or without autologous bone marrow were applied to the defects to evaluate bone regeneration. Both gelatin/β-TCP sponges containing autologous bone marrow and BMP-2-releasing sponges enhanced bone regeneration at the ulna defect to a significantly greater extent than the empty sponges (control). However, in the X-ray-irradiated bone, the bone regeneration either by autologous bone marrow or BMP-2 was inhibited. When combined with autologous bone marrow, the BMP-2 exhibited significantly high osteoinductivity, irrespective of the X-ray irradiation. The bone mineral content at the ulna defect was similar to that of the intact bone. It is concluded that the combination of bone marrow with the BMP-2-releasing gelatin/β-TCP sponge is a promising technique to induce bone regeneration at segmental bone defects after X-ray irradiation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Improvement in degradability of 58s glass scaffolds by ZnO and β-TCP modification

    PubMed Central

    Shuai, Cijun; Cao, Yiyuan; Dan, Gao; Gao, Chengde; Feng, Pei; Wu, Ping

    2016-01-01

    ABSTRACT 58s bioactive glass shows great potential for bone defects repair. However, at early repairing stage, the degradation rate of 58s glass is too fast due to the fast ion-exchange. At later repairing stage, the degradation rate of 58s glass is too slow due to the high dense mineral layer. In this work, Zinc oxide (ZnO) and β-tricalcium phosphate (β-TCP) were introduced into 58s glass bone scaffolds to improve the degradability. The results showed that ZnO could decrease the degradation rate and promote the stability of 58s glass at early repairing stage. Moreover, the presence of β-TCP appeared to increase the degradation rate at a later stage of repairing. Furthermore, in vitro biocompatibility study, carried out using human osteoblast-like cells (MG63), demonstrated that ZnO and β-TCP enhanced cell attachment and proliferation. The study provided a reference for further research in bone tissue engineering. PMID:27710432

  13. Efficacy of rhBMP-2 Loaded PCL/β-TCP/bdECM Scaffold Fabricated by 3D Printing Technology on Bone Regeneration.

    PubMed

    Bae, Eun-Bin; Park, Keun-Ho; Shim, Jin-Hyung; Chung, Ho-Yun; Choi, Jae-Won; Lee, Jin-Ju; Kim, Chang-Hwan; Jeon, Ho-Jun; Kang, Seong-Soo; Huh, Jung-Bo

    2018-01-01

    This study was undertaken to evaluate the effect of 3D printed polycaprolactone (PCL)/ β -tricalcium phosphate ( β -TCP) scaffold containing bone demineralized and decellularized extracellular matrix (bdECM) and human recombinant bone morphogenetic protein-2 (rhBMP-2) on bone regeneration. Scaffolds were divided into PCL/ β -TCP, PCL/ β -TCP/bdECM, and PCL/ β -TCP/bdECM/BMP groups. In vitro release kinetics of rhBMP-2 were determined with respect to cell proliferation and osteogenic differentiation. These three reconstructive materials were implanted into 8 mm diameter calvarial bone defect in male Sprague-Dawley rats. Animals were sacrificed four weeks after implantation for micro-CT, histologic, and histomorphometric analyses. The findings obtained were used to calculate new bone volumes (mm 3 ) and new bone areas (%). Excellent cell bioactivity was observed in the PCL/ β -TCP/bdECM and PCL/ β -TCP/bdECM/BMP groups, and new bone volume and area were significantly higher in the PCL/ β -TCP/bdECM/BMP group than in the other groups ( p < .05). Within the limitations of this study, bdECM printed PCL/ β -TCP scaffolds can reproduce microenvironment for cells and promote adhering and proliferating the cells onto scaffolds. Furthermore, in the rat calvarial defect model, the scaffold which printed rhBMP-2 loaded bdECM stably carries rhBMP-2 and enhances bone regeneration confirming the possibility of bdECM as rhBMP-2 carrier.

  14. Genomewide analysis of TCP transcription factor gene family in Malus domestica.

    PubMed

    Xu, Ruirui; Sun, Peng; Jia, Fengjuan; Lu, Longtao; Li, Yuanyuan; Zhang, Shizhong; Huang, Jinguang

    2014-12-01

    Teosinte branched 1/cycloidea/proliferating cell factor 1 (TCP) proteins are a large family of transcriptional regulators in angiosperms. They are involved in various biological processes, including development and plant metabolism pathways. In this study, a total of 52 TCP genes were identified in apple (Malus domestica) genome. Bioinformatic methods were employed to predicate and analyse their relevant gene classification, gene structure, chromosome location, sequence alignment and conserved domains of MdTCP proteins. Expression analysis from microarray data showed that the expression levels of 28 and 51 MdTCP genes changed during the ripening and rootstock-scion interaction processes, respectively. The expression patterns of 12 selected MdTCP genes were analysed in different tissues and in response to abiotic stresses. All of the selected genes were detected in at least one of the tissues tested, and most of them were modulated by adverse treatments indicating that the MdTCPs were involved in various developmental and physiological processes. To the best of our knowledge, this is the first study of a genomewide analysis of apple TCP gene family. These results provide valuable information for studies on functions of the TCP transcription factor genes in apple.

  15. The use of TCP based EUD to rank and compare lung radiotherapy plans: in-silico study to evaluate the correlation between TCP with physical quality indices.

    PubMed

    Chaikh, Abdulhamid; Balosso, Jacques

    2017-06-01

    To apply the equivalent uniform dose (EUD) radiobiological model to estimate the tumor control probability (TCP) scores for treatment plans using different radiobiological parameter settings, and to evaluate the correlation between TCP and physical quality indices of the treatment plans. Ten radiotherapy treatment plans for lung cancer were generated. The dose distributions were calculated using anisotropic analytical algorithm (AAA). Dose parameters and quality indices derived from dose volume histograms (DVH) for target volumes were evaluated. The predicted TCP was computed using EUD model with tissue-specific parameter (a=-10). The assumed radiobiological parameter setting for adjuvant therapy [tumor dose to control 50% of the tumor (TCD 50 ) =36.5 Gy and γ 50 =0.72] and curative intent (TCD 50 =51.24 Gy and γ 50 =0.83) were used. The bootstrap method was used to estimate the 95% confidence interval (95% CI). The coefficients (ρ) from Spearman's rank test were calculated to assess the correlation between quality indices with TCP. Wilcoxon paired test was used to calculate P value. The 95% CI of TCP were 70.6-81.5 and 46.6-64.7, respectively, for adjuvant radiotherapy and curative intent. The TCP outcome showed a positive and good correlation with calculated dose to 95% of the target volume (D95%) and minimum dose (Dmin). Consistently, TCP correlate negatively with heterogeneity indices. This study confirms that more relevant and robust radiobiological parameters setting should be integrated according to cancer type. The positive correlation with quality indices gives chance to improve the clinical out-come by optimizing the treatment plans to maximize the Dmin and D95%. This attempt to increase the TCP should be carried out with the respect of dose constraints for organs at risks. However, the negative correlation with heterogeneity indices shows that the optimization of beam arrangements could be also useful. Attention should be paid to obtain an appropriate

  16. Enhancement of Perfluoropolyether Boundary Lubrication Performance

    NASA Technical Reports Server (NTRS)

    Jones, W. R., Jr.; Ajayi, O. O.; Wedeven, L. D.

    1996-01-01

    A ball bearing simulator operating under starved conditions was used to perform screening tests to evaluate the boundary lubrication performance of a branched perfluoropolyether (PFPE), K-143 AB. Several approaches to enhance boundary lubrication were studied. These included: (1) soluble boundary additives, (2) bearing surface modifications, (3) 'run-in' surface films, and (4) ceramic bearing components. In addition, results were compared with two non-perfluorinated liquid lubricant formulations. Based on these tests, the following tentative conclusions can be made: (1) Substantial improvements in boundary lubrication performance were observed with a beta-diketone boundary additive and a tricresyl phosphate (TCP) liquid surface pretreatment, (2) the use of rough Si3N4 balls (R(sub a) = 40 micro-inch) also provided increases in test duration, but with concomitant abrasive wear, (3) moderate improvements were seen with two boundary additives (a phosphine and a phosphatriazine) and a neat (100%) fluid (a carboxylic acid terminated PFPE); and small improvements with surface pretreatments with synthetic hydrocarbons, a polytetrafluoroethylene (PTFE) coating, and TiC coated 440 C and smooth Si3N4 balls (R(sub a) = 1 micro-inch), and (4) two non-PFPE lubricant formulations (a polyalphaolefin (PAO) and synthetic hydrocarbon) yielded substantial improvements.

  17. Biofabrication of a PLGA-TCP-based porous bioactive bone substitute with sustained release of icaritin.

    PubMed

    Xie, Xin-Hui; Wang, Xin-Luan; Zhang, Ge; He, Yi-Xin; Leng, Yang; Tang, Ting-Ting; Pan, Xiaohua; Qin, Ling

    2015-08-01

    A phytomolecule, icaritin, has been identified and shown to be osteopromotive for the prevention of osteoporosis and osteonecrosis. This study aimed to produce a bioactive poly (l-lactide-co-glycolide)-tricalcium phosphate (PLGA-TCP)-based porous scaffold incorporating the osteopromotive phytomolecule icaritin, using a fine spinning technology. Both the structure and the composition of icaritin-releasing PLGA-TCP-based scaffolds were evaluated by scanning electron microscopy (SEM). The porosity was quantified by both water absorption and micro-computed tomography (micro-CT). The mechanical properties were evaluated using a compression test. In vitro release of icaritin from the PLGA-TCP scaffold was quantified by high-performance liquid chromatography (HPLC). The attachment, proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) on the composite scaffold were evaluated. Both an in vitro cytotoxicity test and an in vivo test via muscular implantation were conducted to confirm the scaffold's biocompatibility. The results showed that the PLGA-TCP-icaritin composite scaffold was porous, with interconnected macro- (about 480 µm) and micropores (2-15 µm). The mechanical properties of the PLGA-TCP-icaritin scaffold were comparable with those of the pure PLGA-TCP scaffold, yet was spinning direction-dependent. Icaritin content was detected in the medium and increased with time. The PLGA-TCP-icaritin scaffold facilitated the attachment, proliferation and osteogenic differentiation of BMSCs. In vitro cytotoxicity test and in vivo intramuscular implantation showed that the composite scaffold had no toxicity with good biocompatibility. In conclusion, an osteopromotive phytomolecule, icaritin, was successfully incorporated into PLGA-TCP to form an innovative porous composite scaffold with sustained release of osteopromotive icaritin, and this scaffold had good biocompatibility and osteopromotion, suggesting its potential for orthopaedic

  18. SiO2 and ZnO Dopants in 3D Printed TCP Scaffolds Enhances Osteogenesis and Angiogenesis in vivo

    PubMed Central

    Fielding, Gary; Bose, Susmita

    2013-01-01

    Calcium phosphate (CaP) scaffolds with three dimensionally (3D) interconnected pores play an important role in mechanical interlocking and biological fixation in bone implant applications. CaPs alone, however, are only osteoconductive (ability to guide bone growth). Much attention has been given to the incorporation of biologics and pharmacologics to add osteoinductive (ability to cause new bone growth) properties to CaP materials. Because biologics and pharmacologics are generally delicate compounds and also subject to increased regulatory scrutiny, there is a need to investigate alternative methods to introduce osteoinductivity to CaP materials. In this study silica (SiO2) and zinc oxide (ZnO) have been incorporated in to 3D printed β-tricalcium phosphate (TCP) scaffolds to investigate their potential to trigger osteoinduction in vivo. Silicon and zinc are trace elements that are common to bone and have also been shown to have many beneficial properties from increased bone regeneration to angiogenesis. Implants were placed in bicortical femur defects introduced to a murine model for up to 16 weeks. Addition of dopants into TCP increased the capacity for new early bone formation by modulating collagen I production and osteocalcin production. Neovascularization was found to be up to three times more than the pure TCP control group. The findings from this study indicate that the combination of SiO2 and ZnO dopants in TCP may be a viable alternative to introduce osteoinductive properties to CaPs. PMID:23871941

  19. Calorimetry investigations of milled α-tricalcium phosphate (α-TCP) powders to determine the formation enthalpies of α-TCP and X-ray amorphous tricalcium phosphate.

    PubMed

    Hurle, Katrin; Neubauer, Juergen; Bohner, Marc; Doebelin, Nicola; Goetz-Neunhoeffer, Friedlinde

    2015-09-01

    One α-tricalcium phosphate (α-TCP) powder was either calcined at 500°C to obtain fully crystalline α-TCP or milled for different durations to obtain α-TCP powders containing various amounts of X-ray amorphous tricalcium phosphate (ATCP). These powders containing between 0 and 71wt.% ATCP and up to 2.0±0.1wt.% β-TCP as minor phase were then hydrated in 0.1M Na2HPO4 aqueous solution and the resulting heat flows were measured by isothermal calorimetry. Additionally, the evolution of the phase composition during hydration was determined by in situ XRD combined with the G-factor method, an external standard method which facilitates the indirect quantification of amorphous phases. Maximum ATCP hydration was reached after about 1h, while that of crystalline α-TCP hydration occurred between 4 and 11h, depending on the ATCP content. An enthalpy of formation of -4065±6kJ/mol (T=23°C) was calculated for ATCP (Ca3(PO4)2), while for crystalline α-TCP (α-Ca3(PO4)2) a value of -4113±6kJ/mol (T=23°C) was determined. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  20. Repression of cell proliferation by miR319-regulated TCP4.

    PubMed

    Schommer, Carla; Debernardi, Juan M; Bresso, Edgardo G; Rodriguez, Ramiro E; Palatnik, Javier F

    2014-10-01

    Leaf development has been extensively studied on a genetic level. However, little is known about the interplay between the developmental regulators and the cell cycle machinery--a link that ultimately affects leaf form and size. miR319 is a conserved microRNA that regulates TCP transcription factors involved in multiple developmental pathways, including leaf development and senescence, organ curvature, and hormone biosynthesis and signaling. Here, we analyze the participation of TCP4 in the control of cell proliferation. A small increase in TCP4 activity has an immediate impact on leaf cell number, by significantly reducing cell proliferation. Plants with high TCP4 levels have a strong reduction in the expression of genes known to be active in G2-M phase of the cell cycle. Part of these effects is mediated by induction of miR396, which represses Growth-Regulating Factor (GRF) transcription factors. Detailed analysis revealed TCP4 to be a direct regulator of MIR396b. However, we found that TCP4 can control cell proliferation through additional pathways, and we identified a direct connection between TCP4 and ICK1/KRP1, a gene involved in the progression of the cell cycle. Our results show that TCP4 can activate different pathways that repress cell proliferation. © The Author 2014. Published by the Molecular Plant Shanghai Editorial Office in association with Oxford University Press on behalf of CSPB and IPPE, SIBS, CAS.

  1. Comparative phylogenomic analysis provides insights into TCP gene functions in Sorghum.

    PubMed

    Francis, Aleena; Dhaka, Namrata; Bakshi, Mohit; Jung, Ki-Hong; Sharma, Manoj K; Sharma, Rita

    2016-12-05

    Sorghum is a highly efficient C4 crop with potential to mitigate challenges associated with food, feed and fuel. TCP proteins are of particular interest for crop improvement programs due to their well-demonstrated roles in crop domestication and shaping plant architecture thereby, affecting agronomic traits. We identified 20 TCP genes from Sorghum. Except SbTCP8, all are either intronless or contain introns in the untranslated regions. Comparative phylogenetic analysis of Arabidopsis, rice, Brachypodium and Sorghum TCP proteins revealed two distinct classes categorized into ten sub-clades. Sub-clade F is dicot-specific, whereas A2, G1 and I1 groups only contained genes from grasses. Sub-clade B was missing in Sorghum, whereas group A1 was missing in rice indicating species-specific divergence of TCP proteins. TCP proteins of Sorghum are enriched in disorder promoting residues with class I containing higher percent disorder than class II proteins. Seven pairs of paralogous TCP genes were identified from Sorghum, five of which seem to predate Rice-Sorghum divergence. All of them have diverged in their expression. Based on the expression and orthology analysis, five Sorghum genes have been shortlisted for further investigation for their roles in regulating plant morphology. Whereas, three genes have been identified as candidates for engineering abiotic stress tolerance.

  2. The adsorption and thermal decomposition of tricresylphosphate (TCP) on iron and gold

    NASA Technical Reports Server (NTRS)

    Wheeler, D. R.; Faut, O. D.

    1983-01-01

    Because tricresyl-phosphate (TCP) is a common antiwear additive in lubricants, there is great interest in its interactions with metal substrates. The TCP was allowed to adsorb on polycrystalline iron and gold at room temperature. X-ray photoelectron spectroscopy (XPS) was used to analyze the adsorbed species. The substrate was then heated in steps to 330 C, and the changes in the adsorbate were analyzed after each step. On both substrates saturation adsorption occurred at about one monolayer, but the sticking coefficient was less on gold than on iron. Comparison of the XPS spectra of TCP on each substrate with the spectrum from condensed TCP indicated nondissociative adsorption on gold, possibly by dipole-induced dipole interaction. On iron, there was apparently additional interaction between the substrate and the tolyl groups on the TCP molecule. TCP began to desorb molecularly from gold as soon as the gold was heated above room temperature. The desorption was complete by 200 C. However, when the iron substrate was heated, TCP did not desorb but decomposed between 150 and 250 C.

  3. Controlled electrophoretic deposition of HAp/β-TCP composite coatings on piranha treated 316L SS for enhanced mechanical and biological properties

    NASA Astrophysics Data System (ADS)

    Prem Ananth, K.; Nathanael, A. Joseph; Jose, Sujin P.; Oh, Tae Hwan; Mangalaraj, D.; Ballamurugan, A. M.

    2015-10-01

    Hydroxyapatite (HAp) and β-tricalcium phosphate (β-TCP) bioactive materials have been used as individual coatings on steel implants employed in the fields of orthopedics and dentistry due to their excellent properties, which foster effective healing of the repair site. However, slow dissolution of HAp and fairly little fast dissolution of β-TCP present a major obstacle for such applications and this leads to the focus on the investigation of a mixture of HAp and β-TCP composite that forms biphasic calcium phosphate (BCP). The BCP coatings were achieved by thickness controlled electrophoretic deposition on piranha treated 316L SS. This method is well controlled and the anticipated dissolution rate could be attained with faster formation of new bone at the implant site, when compared to the individual HAp or β-TCP coating. The structural, functional, morphological and elemental composition of the coatings were characterized by using various analytical techniques. The BCP coating has been shown to have a role in obstructing the corrosion to a greater extent when in contact with SBF solution. The BCP coating also shows excellent in vitro and mechanical properties and osteoblasts cellular tests revealed that the coating was more effective in improving biocompatibility. This makes it an ideal candidate material for hard tissue replacement.

  4. Controlling Blue and Red Light Emissions from Europium (Eu2+)/Manganese (Mn2+)-Codoped Beta-Tricalcium Phosphate [β-Ca3(PO4)2 (TCP)] Phosphors

    NASA Astrophysics Data System (ADS)

    Van, Hoang Nhu; Hoan, Bui Thi; Nguyen, Khoi Thi; Tam, Phuong Dinh; Huy, Pham Thanh; Pham, Vuong-Hung

    2018-03-01

    Tunable light emission from europium (Eu2+)/manganese (Mn2+)-codoped beta-tricalcium phosphate [β-Ca3(PO4)2 (TCP)] has been investigated as a function of the Mn2+ and Eu2+ concentrations and annealing temperature. Eu2+/Mn2+-doped TCP phosphor (Eu/Mn-TCP) was synthesized by coprecipitation method followed by thermal annealing at temperature up to 1100°C. The Eu2+/Mn2+-doped TCP particles have diameter of about 1 μm. The light emission from TCP is enhanced in the sample with 7.5 mol.% Mn2+ and 0.3 mol.% Eu2+ annealed in Ar + 5% H2 atmosphere at 1100°C. The blue band at 430 nm is attributed to the 4f 6 5d 1-4f 7 transition of Eu2+. The sharp peak at 660 nm is ascribed to the 4T1-6A1 transition of Mn2+ in TCP. These results suggest codoping of Eu2+/Mn2+ to TCP phosphor to obtain β-Ca3(PO4)2:Eu2+,Mn2+ phosphors with tunable luminescence, having potential applications in agricultural lighting.

  5. Comparative phylogenomic analysis provides insights into TCP gene functions in Sorghum

    PubMed Central

    Francis, Aleena; Dhaka, Namrata; Bakshi, Mohit; Jung, Ki-Hong; Sharma, Manoj K.; Sharma, Rita

    2016-01-01

    Sorghum is a highly efficient C4 crop with potential to mitigate challenges associated with food, feed and fuel. TCP proteins are of particular interest for crop improvement programs due to their well-demonstrated roles in crop domestication and shaping plant architecture thereby, affecting agronomic traits. We identified 20 TCP genes from Sorghum. Except SbTCP8, all are either intronless or contain introns in the untranslated regions. Comparative phylogenetic analysis of Arabidopsis, rice, Brachypodium and Sorghum TCP proteins revealed two distinct classes categorized into ten sub-clades. Sub-clade F is dicot-specific, whereas A2, G1 and I1 groups only contained genes from grasses. Sub-clade B was missing in Sorghum, whereas group A1 was missing in rice indicating species-specific divergence of TCP proteins. TCP proteins of Sorghum are enriched in disorder promoting residues with class I containing higher percent disorder than class II proteins. Seven pairs of paralogous TCP genes were identified from Sorghum, five of which seem to predate Rice-Sorghum divergence. All of them have diverged in their expression. Based on the expression and orthology analysis, five Sorghum genes have been shortlisted for further investigation for their roles in regulating plant morphology. Whereas, three genes have been identified as candidates for engineering abiotic stress tolerance. PMID:27917941

  6. Biphasic β-TCP mixed with silicon increases bone formation in critical site defects in rabbit calvaria.

    PubMed

    Calvo-Guirado, José Luis; Garces, Miguel; Delgado-Ruiz, Rafael Arcesio; Ramirez Fernandez, Maria P; Ferres-Amat, Eduard; Romanos, Georgios E

    2015-08-01

    The aim of this study was to assess the bone regeneration of critical size defects in rabbit calvarias filled with β-TCP doped with silicon. Twenty-one New Zealand rabbits were used in this study. Two critical size defects were created in the parietal bones. Three experimental groups were evaluated: Test A (HA/β-TCP granules alone), Test B (HA/β-TCP granules plus 3% silicon), Control (empty defect). The animals were sacrificed at 8 and 12 weeks. Evaluation was performed by μCT analysis and histomorphometry. μCT evaluation showed higher volume reduction in Test A group compared with Test B (P < 0.05). The Test B group showed the highest values for cortical closure and bone formation around the particles, followed by Test A and controls (P < 0.05). Within the limitations of this animal study, it can be concluded that HA/β-TCP plus 3% silicon increases bone formation in critical size defects in rabbit calvarias, and the incorporation of 3% silicon reduces the resorption rate of the HA/β-TCP granules. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Toll/Interleukin-1 Receptor Domain Derived from TcpC (TIR-TcpC) Ameliorates Experimental Autoimmune Arthritis by Down-modulating Th17 Cell Response*

    PubMed Central

    Pasi, Shweta; Kant, Ravi; Surolia, Avadhesha

    2016-01-01

    Evasion through immunomodulation is one of the several strategies adopted by pathogens to prolong their survival within the host. One such pathogen, Escherichia coli CFT073, utilizes an immunomodulatory protein, TcpC, to combat the host's innate immune defense. TcpC abrogates the function of MyD88 in macrophages, thus perturbing all the signaling processes that involve this adaptor protein. Although central to various signaling pathways initiated by IL-1, IL-18, and toll-like receptors, the precise contribution of MyD88 to the development of autoimmunity, particularly rheumatoid arthritis, still needs extensive exploration. Herein, by using the toll/interleukin-1 receptor (TIR) domain homologous C-terminal motif of TcpC, i.e. TIR-TcpC, we found MyD88 to be critical for the induction and progression of rheumatoid arthritis through its pivotal role in the development of Th17 cells, the subset of CD4+ T-cells widely implicated in various autoimmune disorders. The TIR-TcpC mediated inhibition of signaling through MyD88, and subsequent amelioration of experimental autoimmune arthritis was observed to be an outcome of perturbations in the NFκB-RORγt (RAR-related orphan receptor γt) axis. PMID:27022030

  8. Arabidopsis TCP Transcription Factors Interact with the SUMO Conjugating Machinery in Nuclear Foci

    PubMed Central

    Mazur, Magdalena J.; Spears, Benjamin J.; Djajasaputra, André; van der Gragt, Michelle; Vlachakis, Georgios; Beerens, Bas; Gassmann, Walter; van den Burg, Harrold A.

    2017-01-01

    In Arabidopsis more than 400 proteins have been identified as SUMO targets, both in vivo and in vitro. Among others, transcription factors (TFs) are common targets for SUMO conjugation. Here we aimed to exhaustively screen for TFs that interact with the SUMO machinery using an arrayed yeast two-hybrid library containing more than 1,100 TFs. We identified 76 interactors that foremost interact with the SUMO conjugation enzyme SCE1 and/or the SUMO E3 ligase SIZ1. These interactors belong to various TF families, which control a wide range of processes in plant development and stress signaling. Amongst these interactors, the TCP family was overrepresented with several TCPs interacting with different proteins of the SUMO conjugation cycle. For a subset of these TCPs we confirmed that the catalytic site of SCE1 is essential for this interaction. In agreement, TCP1, TCP3, TCP8, TCP14, and TCP15 were readily SUMO modified in an E. coli sumoylation assay. Strikingly, these TCP-SCE1 interactions were found to redistribute these TCPs into nuclear foci/speckles, suggesting that these TCP foci represent sites for SUMO (conjugation) activity. PMID:29250092

  9. The heterologous expression of a chrysanthemum TCP-P transcription factor CmTCP14 suppresses organ size and delays senescence in Arabidopsis thaliana.

    PubMed

    Zhang, Ting; Qu, Yixin; Wang, Haibin; Wang, Jingjing; Song, Aiping; Hu, Yueheng; Chen, Sumei; Jiang, Jiafu; Chen, Fadi

    2017-06-01

    TCP transcription factors are important for plant growth and development, but their activity in chrysanthemum (Chrysanthemum morifolium) has not been thoroughly explored. Here, a chrysanthemum TCP-P sequence, which encodes a protein harboring the conserved basic helix-loop-helix (bHLH) motif, was shown to be related phylogenetically to the Arabidopsis thaliana gene AtTCP14. A yeast-one hybrid assay showed that the encoding protein had no transcriptional activation ability, and a localization experiment indicated that it was localized in the nucleus. Transcription profiling established that the gene was most active in the stem and leaf. Its heterologous expression in A. thaliana down-regulated certain cell cycle-related genes, reduced the size of various organs and increased the chlorophyll and carotenoid contents of the leaf which led to delayed senescence and a prolonged flowering period. Moreover, by screening the cDNA library of chrysanthemum, we found that the CmTCP14 can interact with CmFTL2 and some CmDELLAs. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  10. Engineering biomimetic periosteum with β-TCP scaffolds to promote bone formation in calvarial defects of rats.

    PubMed

    Zhang, Dan; Gao, Peng; Li, Qin; Li, Jinda; Li, Xiaojuan; Liu, Xiaoning; Kang, Yunqing; Ren, Liling

    2017-06-05

    There is a critical need for the management of large bone defects. The purpose of this study was to engineer a biomimetic periosteum and to combine this with a macroporous β-tricalcium phosphate (β-TCP) scaffold for bone tissue regeneration. Rat bone marrow-derived mesenchymal stem cells (rBMSCs) were harvested and cultured in different culture media to form undifferentiated rBMSC sheets (undifferentiated medium (UM)) and osteogenic cell sheets (osteogenic medium (OM)). Simultaneously, rBMSCs were differentiated to induced endothelial-like cells (iECs), and the iECs were further cultured on a UM to form a vascularized cell sheet. At the same time, flow cytometry was used to detect the conversion rates of rBMSCs to iECs. The pre-vascularized cell sheet (iECs/UM) and the osteogenic cell sheet (OM) were stacked together to form a biomimetic periosteum with two distinct layers, which mimicked the fibrous layer and cambium layer of native periosteum. The biomimetic periostea were wrapped onto porous β-TCP scaffolds (BP/β-TCP) and implanted in the calvarial bone defects of rats. As controls, autologous periostea with β-TCP (AP/β-TCP) and β-TCP alone were implanted in the calvarial defects of rats, with a no implantation group as another control. At 2, 4, and 8 weeks post-surgery, implants were retrieved and X-ray, microcomputed tomography (micro-CT), histology, and immunohistochemistry staining analyses were performed. Flow cytometry results showed that rBMSCs were partially differentiated into iECs with a 35.1% conversion rate in terms of CD31. There were still 20.97% rBMSCs expressing CD90. Scanning electron microscopy (SEM) results indicated that cells from the wrapped cell sheet on the β-TCP scaffold apparently migrated into the pores of the β-TCP scaffold. The histology and immunohistochemistry staining results from in vivo implantation indicated that the BP/β-TCP and AP/β-TCP groups promoted the formation of blood vessels and new bone tissues in the bone

  11. Spatial Control of Gene Expression by miR319-Regulated TCP Transcription Factors in Leaf Development.

    PubMed

    Bresso, Edgardo G; Chorostecki, Uciel; Rodriguez, Ramiro E; Palatnik, Javier F; Schommer, Carla

    2018-02-01

    The characteristic leaf shapes we see in all plants are in good part the outcome of the combined action of several transcription factor networks that translate into cell division activity during the early development of the organ. We show here that wild-type leaves have distinct transcriptomic profiles in center and marginal regions. Certain transcripts are enriched in margins, including those of CINCINNATA -like TCPs ( TEOSINTE BRANCHED, CYCLOIDEA and PCF1/2 ) and members of the NGATHA and STYLISH gene families. We study in detail the contribution of microRNA319 (miR319)-regulated TCP transcription factors to the development of the center and marginal regions of Arabidopsis ( Arabidopsis thaliana ) leaves. We compare in molecular analyses the wild type, the tcp2 tcp4 mutant that has enlarged flat leaves, and the tcp2 tcp3 tcp4 tcp10 mutant with strongly crinkled leaves. The different leaf domains of the tcp mutants show changed expression patterns for many photosynthesis-related genes, indicating delayed differentiation, especially in the marginal parts of the organ. At the same time, we found an up-regulation of cyclin genes and other genes that are known to participate in cell division, specifically in the marginal regions of tcp2 tcp3 tcp4 tcp10 Using GUS reporter constructs, we confirmed extended mitotic activity in the tcp2 tcp3 tcp4 tcp10 leaf, which persisted in small defined foci in the margins when the mitotic activity had already ceased in wild-type leaves. Our results describe the role of miR319-regulated TCP transcription factors in the coordination of activities in different leaf domains during organ development. © 2018 American Society of Plant Biologists. All Rights Reserved.

  12. [Biocompatibility of HA/TCP biphasic ceramics with co-cultured human osteoblasts in vitro].

    PubMed

    Lu, X; Li, S; Zhang, J; Zhang, Z; Lu, B; Bu, H; Li, Y; Cheng, J

    2001-12-01

    The biocompatibility of HA/TCP ceramic was evaluated by investigation of attachment and growth of osteoblasts on biomaterial, as well as monitoring the effects of biomaterial on expression of functional phenotypes of co-cultured osteoblasts in vitro. When co-cultured with HA/TCP ceramics, osteoblasts firstly attached to the surface of HA/TCP disk, then attached to notches and grew into the micropores of biomaterial during further culture period. At last, the ceramics were almost packed with osteoblasts. Additionally, osteoblasts co-cultured with HA/TCP were similar to osteoblasts cultured under normal condition in osteoblastic phenotypes; the secreted lots of collagen type I, possess strong activity of Alkaline Phosphatase and mineralized extracellular matrix. The fact that osteoblasts could grow well on HA/TCP ceramics and the biomaterial did not affect their physiological function suggest that HA/TCP ceramic is biocompatible with human osteoblasts.

  13. Novel functions of the Arabidopsis transcription factor TCP5 in petal development and ethylene biosynthesis.

    PubMed

    van Es, Sam W; Silveira, Sylvia R; Rocha, Diego I; Bimbo, Andrea; Martinelli, Adriana P; Dornelas, Marcelo C; Angenent, Gerco C; Immink, Richard G H

    2018-06-01

    The flowers of most dicotyledons have petals that, together with the sepals, initially protect the reproductive organs. Later during development petals are required to open the flower and to attract pollinators. This diverse set of functions demands tight temporal and spatial regulation of petal development. We studied the functioning of the Arabidopsis thaliana TCP5-like transcription factors (TFs) in petals. Overexpression of TCP5 in petal epidermal cells results in smaller petals, whereas tcp5 tcp13 tcp17 triple knockout lines have wider petals with an increased surface area. Comprehensive expression studies revealed effects of TCP5-like TFs on the expression of genes related to the cell cycle, growth regulation and organ growth. Additionally, the ethylene biosynthesis genes 1-amino-cyclopropane-1-carboxylate (ACC) synthase 2 (ACS2) and ACC oxidase 2 (ACO2) and several ETHYLENE RESPONSE FACTORS (ERFs) are found to be differentially expressed in TCP5 mutant and overexpression lines. Chromatin immunoprecipitation-quantitative PCR showed direct binding of TCP5 to the ACS2 locus in vivo. Ethylene is known to influence cell elongation, and the petal phenotype of the tcp5 tcp13 tcp17 mutant could be complemented by treatment of the plants with an ethylene pathway inhibitor. Taken together, this reveals a novel role for TCP5-like TFs in the regulation of ethylene-mediated petal development and growth. © 2018 The Authors The Plant Journal published by John Wiley & Sons Ltd and Society for Experimental Biology.

  14. Crystal structure of the Vibrio cholerae colonization factor TcpF and identification of a functional immunogenic site.

    PubMed

    Megli, Christina J; Yuen, Alex S W; Kolappan, Subramaniapillai; Richardson, Malcolm R; Dharmasena, Madushini N; Krebs, Shelly J; Taylor, Ronald K; Craig, Lisa

    2011-06-03

    Vibrio cholerae relies on two main virulence factors--toxin-coregulated pilus (TCP) and cholera toxin--to cause the gastrointestinal disease cholera. TCP is a type IV pilus that mediates bacterial autoagglutination and colonization of the intestine. TCP is encoded by the tcp operon, which also encodes TcpF, a protein of unknown function that is secreted by V. cholerae in a TCP-dependent manner. Although TcpF is not required for TCP biogenesis, a tcpF mutant has a colonization defect in the infant mouse cholera model that is as severe as a pilus mutant. Furthermore, TcpF antisera protect against V. cholerae infection. TcpF has no apparent sequence homology to any known protein. Here, we report the de novo X-ray crystal structure of TcpF and the identification of an epitope that is critical for its function as a colonization factor. A monoclonal antibody recognizing this epitope is protective against V. cholerae challenge and adds to the protection provided by an anti-TcpA antibody. These data suggest that TcpF has a novel function in V. cholerae colonization and define a region crucial for this function. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. TCP10L acts as a tumor suppressor by inhibiting cell proliferation in hepatocellular carcinoma

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zuo, Jie; Cai, Hao; Wu, Yanhua

    2014-03-28

    Highlights: • TCP10L was down-regulated in clinical hepatocellular carcinoma (HCC). • Expression of TCP10L correlated significantly with tumor size and Milan criteria. • Overexpression of TCP10L attenuated growth of HCC cells both in vitro and in vivo. • Knocking down TCP10L promoted cell proliferation and tumorigenesis of HCC cells. - Abstract: TCP10L (T-complex 10 (mouse)-like) has been identified as a liver and testis-specific gene. Although a potential transcriptional suppression function of TCP10L has been reported previously, biological function of this gene still remains largely elusive. In this study, we reported for the first time that TCP10L was significantly down-regulated inmore » clinical hepatocellular carcinoma (HCC) samples when compared to the corresponding non-tumorous liver tissues. Furthermore, TCP10L expression was highly correlated with advanced cases exceeding the Milan criteria. Overexpression of TCP10L in HCC cells suppressed colony formation, inhibited cell cycle progression through G0/G1 phase, and attenuated cell growth in vivo. Consistently, silencing of TCP10L promoted cell cycle progression and cell growth. Therefore, our study has revealed a novel suppressor role of TCP10L in HCC, by inhibiting proliferation of HCC cells, which may facilitate the diagnosis and molecular therapy in HCC.« less

  16. 3D printed scaffolds of calcium silicate-doped β-TCP synergize with co-cultured endothelial and stromal cells to promote vascularization and bone formation.

    PubMed

    Deng, Yuan; Jiang, Chuan; Li, Cuidi; Li, Tao; Peng, Mingzheng; Wang, Jinwu; Dai, Kerong

    2017-07-17

    Synthetic bone scaffolds have potential application in repairing large bone defects, however, inefficient vascularization after implantation remains the major issue of graft failure. Herein, porous β-tricalcium phosphate (β-TCP) scaffolds with calcium silicate (CS) were 3D printed, and pre-seeded with co-cultured human umbilical cord vein endothelial cells (HUVECs) and human bone marrow stromal cells (hBMSCs) to construct tissue engineering scaffolds with accelerated vascularization and better bone formation. Results showed that in vitro β-TCP scaffolds doped with 5% CS (5%CS/β-TCP) were biocompatible, and stimulated angiogenesis and osteogenesis. The results also showed that 5%CS/β-TCP scaffolds not only stimulated co-cultured cells angiogenesis on Matrigel, but also stimulated co-cultured cells to form microcapillary-like structures on scaffolds, and promoted migration of BMSCs by stimulating co-cultured cells to secrete PDGF-BB and CXCL12 into the surrounding environment. Moreover, 5%CS/β-TCP scaffolds enhanced vascularization and osteoinduction in comparison with β-TCP, and synergized with co-cultured cells to further increase early vessel formation, which was accompanied by earlier and better ectopic bone formation when implanted subcutaneously in nude mice. Thus, our findings suggest that porous 5%CS/β-TCP scaffolds seeded with co-cultured cells provide new strategy for accelerating tissue engineering scaffolds vascularization and osteogenesis, and show potential as treatment for large bone defects.

  17. TCP transcription factors are critical for the coordinated regulation of isochorismate synthase 1 expression in Arabidopsis thaliana.

    PubMed

    Wang, Xiaoyan; Gao, Jiong; Zhu, Zheng; Dong, Xianxin; Wang, Xiaolei; Ren, Guodong; Zhou, Xin; Kuai, Benke

    2015-04-01

    Salicylic acid (SA) plays an important role in various aspects of plant development and responses to stresses. To elucidate the sophisticated regulatory mechanism of SA synthesis and signaling, we used a yeast one-hybrid system to screen for regulators of isochorismate synthase 1 (ICS1), a gene encoding the key enzyme in SA biosynthesis in Arabidopsis thaliana. A TCP family transcription factor AtTCP8 was initially identified as a candidate regulator of ICS1. The regulation of ICS1 by TCP proteins is supported by the presence of a typical TCP binding site in the ICS1 promoter. The binding of TCP8 to this site was confirmed by in vitro and in vivo assays. Expression patterns of TCP8 and its corresponding gene TCP9 largely overlapped with ICS1 under pathogen attack. A significant reduction in the expression of ICS1 during immune responses was observed in the tcp8 tcp9 double mutant. We also detected strong interactions between TCP8 and SAR deficient 1 (SARD1), WRKY family transcription factor 28 (WRKY28), NAC (NAM/ATAF1,ATAF2/CUC2) family transcription factor 019 (NAC019), as well as among TCP8, TCP9 and TCP20, suggesting a complex coordinated regulatory mechanism underlying ICS1 expression. Our results collectively demonstrate that TCP proteins are involved in the orchestrated regulation of ICS1 expression, with TCP8 and TCP9 being verified as major representatives. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  18. Biocompatibility and biodegradation studies of PCL/β-TCP bone tissue scaffold fabricated by structural porogen method.

    PubMed

    Lu, Lin; Zhang, Qingwei; Wootton, David; Chiou, Richard; Li, Dichen; Lu, Bingheng; Lelkes, Peter; Zhou, Jack

    2012-09-01

    Three-dimensional printer (3DP) (Z-Corp) is a solid freeform fabrication system capable of generating sub-millimeter physical features required for tissue engineering scaffolds. By using plaster composite materials, 3DP can fabricate a universal porogen which can be injected with a wide range of high melting temperature biomaterials. Here we report results toward the manufacture of either pure polycaprolactone (PCL) or homogeneous composites of 90/10 or 80/20 (w/w) PCL/beta-tricalcium phosphate (β-TCP) by injection molding into plaster composite porogens fabricated by 3DP. The resolution of printed plaster porogens and produced scaffolds was studied by scanning electron microscopy. Cytotoxicity test on scaffold extracts and biocompatibility test on the scaffolds as a matrix supporting murine osteoblast (7F2) and endothelial hybridoma (EAhy 926) cells growth for up to 4 days showed that the porogens removal process had only negligible effects on cell proliferation. The biodegradation tests of pure PCL and PCL/β-TCP composites were performed in DMEM with 10 % (v/v) FBS for up to 6 weeks. The PCL/β-TCP composites show faster degradation rate than that of pure PCL due to the addition of β-TCP, and the strength of 80/20 PCL/β-TCP composite is still suitable for human cancellous bone healing support after 6 weeks degradation. Combining precisely controlled porogen fabrication structure, good biocompatibility, and suitable mechanical properties after biodegradation, PCL/β-TCP scaffolds fabricated by 3DP porogen method provide essential capability for bone tissue engineering.

  19. Osteoinductive potential of highly purified porous β-TCP in mice.

    PubMed

    Tsukanaka, Masako; Fujibayashi, Shunsuke; Otsuki, Bungo; Takemoto, Mitsuru; Matsuda, Shuichi

    2015-03-01

    Material-induced osteoinduction of calcium phosphate ceramics has been reported in specific animals. We previously reported that recruitment of tartrate-resistant acid phosphatase (TRAP)-positive cells might be one of the main factors responsible for the difference in the occurrence of material-induced osteoinduction between dogs and rats. In this study, we evaluated the osteoinductive potential of highly purified porous beta-tricalcium phosphate materials (HPP-β-TCP) with two different porosities, 75 and 60 % (Olympus Terumo Biomaterials, Tokyo, Japan), implanted into subcutaneous pockets of FVB and C57BL/6 mice. Twelve weeks after implantation, histological examination and gene expression analysis using reverse transcription-polymerase chain reaction were performed. We observed osteoinduction in half of the HPP-β-TCP materials with 60 % porosity implanted into FVB mice. This group of mice also exhibited the most TRAP-positive cells. Significantly more vessels were found in FVB mice than in C57BL/6 mice, but the greatest number of vessels was counted in implants from materials with 75 % porosity implanted into FVB mice, which did not show osteoinduction. These results indicate that recruitment of TRAP-positive cells is one factor responsible for osteoinduction caused by HPP-β-TCP materials in both FVB mice and dogs. Vessel formation seems to be necessary but appears to be less influential for osteoinduction than TRAP-positive cell recruitment.

  20. Evaluation of rhBMP-2/collagen/TCP-HA bone graft with and without bone marrow cells in the canine femoral multi defect model.

    PubMed

    Luangphakdy, V; Shinohara, K; Pan, H; Boehm, C; Samaranska, A; Muschler, G F

    2015-01-12

    Recombinant human bone morphogenetic protein-2, when applied to an absorbable type 1 bovine collagen sponge (rhBMP-2/ACS) is an effective therapy in many bone grafting settings. Bone marrow aspirate (BMA) has also been used as a source of transplantable osteogenic connective tissue progenitors. This study was designed to characterize the performance of a scaffold comprising rhBMP-2/ACS in which the sponge wraps around tri-calcium phosphate hydroxyapatite granules (rhBMP-2/ACS/TCP-HA) and to test the hypothesis that addition of BMA will improve the performance of this construct in the Canine Femoral Multi Defect Model. In each subject, two sites were grafted with rhBMP-2/ACS/TCP-HA scaffold loaded with BMA clot and two other sites with rhBMP-2/ACS/TCP-HA scaffold loaded with wound blood (WB). After correction for unresorbed TCP-HA granules, sites grafted with rhBMP-2/ACS/TCP-HA+BMA and rhBMP-2/ACS/TCP-HA+WB were similar, with mean percent bone volumes of 10.9 %±1.2 and 11.2 %±1.2, respectively. No differences were seen in quantitative histomorphometry. While bone formation using both constructs was robust, this study did not support the hypothesis that the addition of unprocessed bone marrow aspirate clot improved bone regeneration in a site engrafted with rhBMP-2/ACS/TCP-HA+BMA. In contrast to prior studies using this model, new bone formation was greater at the center of the defect where TCP-HA was distributed. This finding suggests a potential synergy between rhBMP-2 and the centrally placed ceramic and cellular components of the graft construct. Further optimization may also require more uniform distribution of TCP-HA, alternative cell delivery strategies, and a more rigorous large animal segmental defect model.

  1. Hierarchical structures of β-TCP/45S5 bioglass hybrid scaffolds prepared by gelcasting.

    PubMed

    Lopes, João Henrique; Magalhães, Jéssica Aparecida; Gouveia, Rubia Figueredo; Bertran, Celso Aparecido; Motisuke, Mariana; Camargo, Samira E A; Trichês, Eliandra de Sousa

    2016-09-01

    This paper investigates the microstructure and the mechanical properties of β-tricalcium phosphate (β-TCP) three-dimensional (3D) porous materials reinforced with 45S5 bioactive glass (BG). β-TCP and β-TCP/x%-BG scaffolds with interconnected pores networks, suitable for bone regeneration, were fabricated by gel-casting method. Mechanical properties, porosity, and morphological characteristics were evaluated by compressive strength test, scanning electron microscopy (SEM) and X-ray microtomography analysis, whereas the structures were fully explored by XRD, and Raman spectroscopy. To the best of our knowledge, this is the first time where the mechanism for understanding the effect of bioglass on the mechanical properties and microstruture of β-TCP/45S5-BG scaffolds has been systematically studied. The findings showed that ionic product lixiviated from 45S5 bioactive glass, rich in silicon species and sodium ion, catalyzes a phase transition from β-TCP to Si-TCP by replacement of phosphorus for silicon and contributes to the improvement of scaffolds mechanical properties. The compressive strength of β-TCP/5%-BG and β-TCP/7.5%-BG was improved around 200% in comparison to pure β-TCP. Osteoblast-like cells (MG 63) were exposed to the materials for 24h through the use of medium conditioned by β-tricalcium phosphate/bioactive glass. Cell viability was measured by MTT assay in the cells and the data obtained were submitted to ANOVA, Tukey׳s multiple comparison (p<0.05). The β-TCP/7.5-BG promoted an increase of cell proliferation. The results suggest that compositions and processing method studied may provide appropriate materials for tissue engineering. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. TCP is hardly resorbed and not osteoconductive in a non-loading calvarial model.

    PubMed

    Handschel, Jörg; Wiesmann, Hans Peter; Stratmann, Udo; Kleinheinz, Johannes; Meyer, Ulrich; Joos, Ulrich

    2002-04-01

    Tricalciumphosphate (TCP) has been used as a ceramic bone substitute material in the orthopedic field as well as in craniofacial surgery. Some controversies exist concerning the osteoconductive potential of this material in different implantation sites. This study was designed to evaluate the biological response of calvarial bone towards TCP granules under non-loading conditions to assess the potential of TCP as a biodegredable and osteoconductive bone substitue material for the cranial vault. Full-thickness non-critical size defects were made bilaterally in the calvaria of 21 adult Wistar rats. One side was filled by TCP granules, the contralateral side was left empty and used as a control. Animals were sacrified in defined time intervals up to 6 months. Bone regeneration was analyzed with special respect toward the micromorphological and microanalytical features of the material-bone interaction by electron microscopy and electron diffraction analysis. Histologic examination revealed no TCP degradation even after 6 months of implantation. In contrast, a nearly complete bone regeneration of control defects was found after 6 months. At all times TCP was surrounded by a thin fibrous layer without presence of osteoblasts and features of regular mineralization. As far as degradation and substitution are concerned, TCP is a less favourable material tinder conditions of non-loading.

  3. Genome-Wide Identification, Characterization and Expression Analysis of the TCP Gene Family in Prunus mume

    PubMed Central

    Zhou, Yuzhen; Xu, Zongda; Zhao, Kai; Yang, Weiru; Cheng, Tangren; Wang, Jia; Zhang, Qixiang

    2016-01-01

    TCP proteins, belonging to a plant-specific transcription factors family, are known to have great functions in plant development, especially flower and leaf development. However, there is little information about this gene family in Prunus mume, which is widely cultivated in China as an ornamental and fruit tree. Here a genome-wide analysis of TCP genes was performed to explore their evolution in P. mume. Nineteen PmTCPs were identified and three of them contained putative miR319 target sites. Phylogenetic and comprehensive bioinformatics analyses of these genes revealed that different types of TCP genes had undergone different evolutionary processes and the genes in the same clade had similar chromosomal location, gene structure, and conserved domains. Expression analysis of these PmTCPs indicated that there were diverse expression patterns among different clades. Most TCP genes were predominantly expressed in flower, leaf, and stem, and showed high expression levels in the different stages of flower bud differentiation, especially in petal formation stage and gametophyte development. Genes in TCP-P subfamily had main roles in both flower development and gametophyte development. The CIN genes in double petal cultivars might have key roles in the formation of petal, while they were correlated with gametophyte development in the single petal cultivar. The CYC/TB1 type genes were highly detected in the formation of petal and pistil. The less-complex flower types of P. mume might result from the fact that there were only two CYC type genes present in P. mume and a lack of CYC2 genes to control the identity of flower types. These results lay the foundation for further study on the functions of TCP genes during flower development. PMID:27630648

  4. Genome-Wide Identification, Characterization and Expression Analysis of the TCP Gene Family in Prunus mume.

    PubMed

    Zhou, Yuzhen; Xu, Zongda; Zhao, Kai; Yang, Weiru; Cheng, Tangren; Wang, Jia; Zhang, Qixiang

    2016-01-01

    TCP proteins, belonging to a plant-specific transcription factors family, are known to have great functions in plant development, especially flower and leaf development. However, there is little information about this gene family in Prunus mume, which is widely cultivated in China as an ornamental and fruit tree. Here a genome-wide analysis of TCP genes was performed to explore their evolution in P. mume. Nineteen PmTCPs were identified and three of them contained putative miR319 target sites. Phylogenetic and comprehensive bioinformatics analyses of these genes revealed that different types of TCP genes had undergone different evolutionary processes and the genes in the same clade had similar chromosomal location, gene structure, and conserved domains. Expression analysis of these PmTCPs indicated that there were diverse expression patterns among different clades. Most TCP genes were predominantly expressed in flower, leaf, and stem, and showed high expression levels in the different stages of flower bud differentiation, especially in petal formation stage and gametophyte development. Genes in TCP-P subfamily had main roles in both flower development and gametophyte development. The CIN genes in double petal cultivars might have key roles in the formation of petal, while they were correlated with gametophyte development in the single petal cultivar. The CYC/TB1 type genes were highly detected in the formation of petal and pistil. The less-complex flower types of P. mume might result from the fact that there were only two CYC type genes present in P. mume and a lack of CYC2 genes to control the identity of flower types. These results lay the foundation for further study on the functions of TCP genes during flower development.

  5. Basic research and clinical application of beta-tricalcium phosphate (β-TCP).

    PubMed

    Tanaka, T; Komaki, H; Chazono, M; Kitasato, S; Kakuta, A; Akiyama, S; Marumo, K

    2017-09-01

    The mechanism of bone substitute resorption involves two processes: solution-mediated and cell-mediated disintegration. In our previous animal studies, the main resorption process of beta-tricalcium phosphate (β-TCP) was considered to be cell-mediated disintegration by TRAP-positive cells. Thus, osteoclast-mediated resorption of β-TCP is important for enabling bone formation. We also report the results of treatment with β-TCP graft in patients since 1989. Two to three weeks after implantation, resorption of β-TCP occurred from the periphery, and then continued toward the center over time. Complete or nearly complete bone healing was achieved in most cases within a few years and was dependent upon the amount of implanted material, the patient's age, and the type of bone (cortical or cancellous). We have previously reported that an injectable complex of β-TCP granules and collagen supplemented with rhFGF-2 enabled cortical bone regeneration of rabbit tibiae. Based on the experimental results, we applied this technique to the patients with femoral and humeral fractures in elderly patients, and obtained bone union. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  6. LWD-TCP complex activates the morning gene CCA1 in Arabidopsis.

    PubMed

    Wu, Jing-Fen; Tsai, Huang-Lung; Joanito, Ignasius; Wu, Yi-Chen; Chang, Chin-Wen; Li, Yi-Hang; Wang, Ying; Hong, Jong Chan; Chu, Jhih-Wei; Hsu, Chao-Ping; Wu, Shu-Hsing

    2016-10-13

    A double-negative feedback loop formed by the morning genes CIRCADIAN CLOCK ASSOCIATED1 (CCA1)/LATE ELONGATED HYPOCOTYL (LHY) and the evening gene TIMING OF CAB EXPRESSION1 (TOC1) contributes to regulation of the circadian clock in Arabidopsis. A 24-h circadian cycle starts with the peak expression of CCA1 at dawn. Although CCA1 is targeted by multiple transcriptional repressors, including PSEUDO-RESPONSE REGULATOR9 (PRR9), PRR7, PRR5 and CCA1 HIKING EXPEDITION (CHE), activators of CCA1 remain elusive. Here we use mathematical modelling to infer a co-activator role for LIGHT-REGULATED WD1 (LWD1) in CCA1 expression. We show that the TEOSINTE BRANCHED 1-CYCLOIDEA-PCF20 (TCP20) and TCP22 proteins act as LWD-interacting transcriptional activators. The concomitant binding of LWD1 and TCP20/TCP22 to the TCP-binding site in the CCA1 promoter activates CCA1. Our study reveals activators of the morning gene CCA1 and provides an action mechanism that ensures elevated expression of CCA1 at dawn to sustain a robust clock.

  7. LWD–TCP complex activates the morning gene CCA1 in Arabidopsis

    PubMed Central

    Wu, Jing-Fen; Tsai, Huang-Lung; Joanito, Ignasius; Wu, Yi-Chen; Chang, Chin-Wen; Li, Yi-Hang; Wang, Ying; Hong, Jong Chan; Chu, Jhih-Wei; Hsu, Chao-Ping; Wu, Shu-Hsing

    2016-01-01

    A double-negative feedback loop formed by the morning genes CIRCADIAN CLOCK ASSOCIATED1 (CCA1)/LATE ELONGATED HYPOCOTYL (LHY) and the evening gene TIMING OF CAB EXPRESSION1 (TOC1) contributes to regulation of the circadian clock in Arabidopsis. A 24-h circadian cycle starts with the peak expression of CCA1 at dawn. Although CCA1 is targeted by multiple transcriptional repressors, including PSEUDO-RESPONSE REGULATOR9 (PRR9), PRR7, PRR5 and CCA1 HIKING EXPEDITION (CHE), activators of CCA1 remain elusive. Here we use mathematical modelling to infer a co-activator role for LIGHT-REGULATED WD1 (LWD1) in CCA1 expression. We show that the TEOSINTE BRANCHED 1-CYCLOIDEA-PCF20 (TCP20) and TCP22 proteins act as LWD-interacting transcriptional activators. The concomitant binding of LWD1 and TCP20/TCP22 to the TCP-binding site in the CCA1 promoter activates CCA1. Our study reveals activators of the morning gene CCA1 and provides an action mechanism that ensures elevated expression of CCA1 at dawn to sustain a robust clock. PMID:27734958

  8. OSI and TCP/IP

    NASA Technical Reports Server (NTRS)

    Randolph, Lynwood P.

    1994-01-01

    The Open Systems Interconnection Transmission Control Protocol/Internet Protocol (OSI TCP/IP) and the Government Open Systems Interconnection Profile (GOSIP) are compared and described in terms of Federal internetworking. The organization and functions of the Federal Internetworking Requirements Panel (FIRP) are discussed and the panel's conclusions and recommendations with respect to the standards and implementation of the National Information Infrastructure (NII) are presented.

  9. Evaluation of autogenous PRGF+β-TCP with or without a collagen membrane on bone formation and implant osseointegration in large size bone defects. A preclinical in vivo study.

    PubMed

    Batas, Leonidas; Stavropoulos, Andreas; Papadimitriou, Serafim; Nyengaard, Jens R; Konstantinidis, Antonios

    2016-08-01

    The aim of this study was to evaluate whether the adjunctive use of a collagen membrane enhances bone formation and implant osseointegration in non-contained defects grafted with chair-side prepared autologous platelet-rich growth factor (PRGF) adsorbed on a β-TCP particulate carrier. Large box-type defects (10 × 6 mm; W × D) were prepared in the edentulated and completely healed mandibles of six Beagles dogs. An implant with moderately rough surface was placed in the center of each defect leaving the coronal 6 mm of the implant not covered with bone. The remaining defect space was then filled out with chair-side prepared autologous PRGF adsorbed on β-TCP particles and either covered with a collagen membrane (PRGF/β-TCP+CM) (6 defects) or left without a membrane (PRGF/β-TCP) (5 defects). Histology 4 months post-op showed new lamellar and woven bone formation encompassing almost entirely the defect and limited residual β-TCP particles. Extent of osseointegration of the previously exposed portion of the implants varied, but in general was limited. Within the defect, new mineralized bone (%) averaged 43.2 ± 9.86 vs. 39.9 ± 13.7 in the PRGF/β-TCP+CM and PRGF/β-TCP group (P = 0.22) and relative mineralized bone-to-implant contact (%) averaged 26.2 ± 16.45 vs. 35.91 ± 24.45, respectively (P = 0.5). First, bone-to-implant contact from the implant top was 4.1 ± 1.5 and 3.2 ± 2.3 (P = 0.9), in the PRGF/β-TCP+CM and PRGF/β-TCP group, respectively. Implantation of chair-side prepared autologous PRGF adsorbed on a β-TCP carrier in non-contained peri-implant defects resulted in large amounts of bone regeneration, but osseointegration was limited. Provisions for GBR with a collagen membrane did not significantly enhance bone regeneration or implant osseointegration. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Efficacy of Honeycomb TCP-induced Microenvironment on Bone Tissue Regeneration in Craniofacial Area.

    PubMed

    Watanabe, Satoko; Takabatake, Kiyofumi; Tsujigiwa, Hidetsugu; Watanabe, Toshiyuki; Tokuyama, Eijiro; Ito, Satoshi; Nagatsuka, Hitoshi; Kimata, Yoshihiro

    2016-01-01

    Artificial bone materials that exhibit high biocompatibility have been developed and are being widely used for bone tissue regeneration. However, there are no biomaterials that are minimally invasive and safe. In a previous study, we succeeded in developing honeycomb β-tricalcium phosphate (β-TCP) which has through-and-through holes and is able to mimic the bone microenvironment for bone tissue regeneration. In the present study, we investigated how the difference in hole-diameter of honeycomb β-TCP (hole-diameter: 75, 300, 500, and 1600 μm) influences bone tissue regeneration histologically. Its osteoconductivity was also evaluated by implantation into zygomatic bone defects in rats. The results showed that the maximum bone formation was observed on the β-TCP with hole-diameter 300μm, included bone marrow-like tissue and the pattern of bone tissue formation similar to host bone. Therefore, the results indicated that we could control bone tissue formation by creating a bone microenvironment provided by β-TCP. Also, in zygomatic bone defect model with honeycomb β-TCP, the result showed there was osseous union and the continuity was reproduced between the both edges of resected bone and β-TCP, which indicated the zygomatic bone reproduction fully succeeded. It is thus thought that honeycomb β-TCP may serve as an excellent biomaterial for bone tissue regeneration in the head, neck and face regions, expected in clinical applications.

  11. Poly (γ-glutamic acid)/beta-TCP nanocomposites via in situ copolymerization: Preparation and characterization.

    PubMed

    Shu, Xiu-Lin; Shi, Qing-Shan; Feng, Jin; Yang, Yun-Hua; Zhou, Gang; Li, Wen-Ru

    2016-07-01

    A series biodegradable poly (γ-glutamic acid)/beta-tricalcium phosphate (γ-PGA/TCP) nanocomposites were prepared which were composed of poly-γ-glutamic acid polymerized in situ with β-tricalcium phosphate and physiochemically characterized as bone graft substitutes. The particle size via dynamic light scattering, the direct morphological characterization via transmission electron microscopy and field emission scanning electron microscope, which showed that γ-PGA and β-TCP were combined compactly at 80℃, and the γ-PGA/TCP nanocomposites had homogenous and nano-sized grains with narrow particle size distributions. The water uptake and retention abilities, in vitro degradation properties, cytotoxicity in the simulated medium, and protein release of these novel γ-PGA/TCP composites were investigated. Cell proliferation in composites was nearly twice than β-TCP when checked in vitro using MC3T3 cell line. We also envision the potential use of γ-PGA/TCP systems in bone growth factor or orthopedic drug delivery applications in future bone tissue engineering applications. These observations suggest that the γ-PGA/TCP are novel nanocomposites with great potential for application in the field of bone tissue engineering. © The Author(s) 2016.

  12. Treatment of periodontal intrabony defects using β-TCP alone or in combination with rhPDGF-BB: a randomized controlled clinical and radiographic study.

    PubMed

    Maroo, Sneha; Murthy, K Raja V

    2014-01-01

    The need to increase the predictability of periodontal regeneration has encouraged clinicians and researchers to employ cell-stimulating proteins in combination with osteoconductive scaffolds, based on the principles of tissue engineering. The purpose of this clinical and radiographic study was to compare the regenerative potential of the combination of β-tricalcium phosphate (β-TCP) and recombinant human platelet-derived growth factor BB (rhPDGF-BB) in the grafting of intraosseous defects with the established technique of bone grafting with (β-TCP alone. A total of 30 sites from 15 patients with infrabony defects in two different quadrants were selected, and the sites were randomly divided into test sites (rhPDGF + β-TCP) and control sites (β-TCP alone) using a split-mouth design. Clinical parameters, including probing pocket depth, clinical attachment level, and gingival recession, were recorded at baseline, 6 months, and 9 months. Radiographic evaluation was carried out to evaluate defect fill, change in alveolar crest height, and percentage of defect fill at baseline, 6 months, and 9 months. Both the experimental groups showed statistically significant reduction in probing pocket depth and gain in clinical attachment level. On intergroup comparison, sites treated with rhPDGF + β-TCP demonstrated a significantly greater pocket depth reduction (P < .05) and greater gain in clinical attachment level (P < .01). Mean percentage defect fill was significantly greater in test sites as compared with control sites at 6 and 9 months (P < .01). rhPDGF + β-TCP-treated sites demonstrated a significant gain in mean alveolar crest height at 6 and 9 months (P < .05), while β-TCP-treated sites demonstrated crestal resorption. Both groups demonstrated potential in enhancing periodontal regeneration; however, on comparison between the two groups, the results obtained by rhPDGF + β-TCP were significantly better with respect to both clinical and radiographic parameters.

  13. The Vibrio cholerae Minor Pilin TcpB Initiates Assembly and Retraction of the Toxin-Coregulated Pilus.

    PubMed

    Ng, Dixon; Harn, Tony; Altindal, Tuba; Kolappan, Subramania; Marles, Jarrad M; Lala, Rajan; Spielman, Ingrid; Gao, Yang; Hauke, Caitlyn A; Kovacikova, Gabriela; Verjee, Zia; Taylor, Ronald K; Biais, Nicolas; Craig, Lisa

    2016-12-01

    Type IV pilus (T4P) systems are complex molecular machines that polymerize major pilin proteins into thin filaments displayed on bacterial surfaces. Pilus functions require rapid extension and depolymerization of the pilus, powered by the assembly and retraction ATPases, respectively. A set of low abundance minor pilins influences pilus dynamics by unknown mechanisms. The Vibrio cholerae toxin-coregulated pilus (TCP) is among the simplest of the T4P systems, having a single minor pilin TcpB and lacking a retraction ATPase. Here we show that TcpB, like its homolog CofB, initiates pilus assembly. TcpB co-localizes with the pili but at extremely low levels, equivalent to one subunit per pilus. We used a micropillars assay to demonstrate that TCP are retractile despite the absence of a retraction ATPase, and that retraction relies on TcpB, as a V. cholerae tcpB Glu5Val mutant is fully piliated but does not induce micropillars movements. This mutant is impaired in TCP-mediated autoagglutination and TcpF secretion, consistent with retraction being required for these functions. We propose that TcpB initiates pilus retraction by incorporating into the growing pilus in a Glu5-dependent manner, which stalls assembly and triggers processive disassembly. These results provide a framework for understanding filament dynamics in more complex T4P systems and the closely related Type II secretion system.

  14. DETERMINATION OF 3,5,6-TRICHLORO-2-PYRIDINOL (TCP) BY ELISA

    EPA Science Inventory

    A sensitive, competitive enzyme-linked immunosorbent assay (ELISA) for 3,5,6-trichloro-2pyridinol (TCP) has been developed to quantitate parts per billion (ppb) amounts of the analyte in urine. TCP is a major metabolite and environmental degradation product of the insecticide c...

  15. Development of bioactive porous α-TCP/HAp beads for bone tissue engineering.

    PubMed

    Asaoka, Teruo; Ohtake, Shoji; Furukawa, Katsuko S; Tamura, Akito; Ushida, Takashi

    2013-11-01

    Porous beads of bioactive ceramics such as hydroxyapatite (HAp) and tribasic calcium phosphate (TCP) are considered a promising scaffold for cultivating bone cells. To realize this, α-TCP/HAp functionally graded porous beads are fabricated with two main purposes: to maintain the function of the scaffold with sufficient strength up to the growth of new bone, and is absorbed completely after the growth. HAp is a bioactive material that has both high strength and strong tissue-adhesive properties, but is not readily absorbed by the human body. On the contrary, α-TCP is highly bioabsorbable, resulting in a scaffold that is absorbed before it is completely replaced by bone. In this study, we produced porous, bead-shaped carriers as scaffolds for osteoblast culture. To control the solubility in vivo, the fabricated beads contained α-TCP at the center and HAp at the surface. Cell adaptability of these beads for bone tissue engineering was confirmed in vitro. It was found that α-TCP/HAp bead carriers exhibit low toxicity in the initial stages of cell seeding and cell adhesion. The presence of HAp in the composite bead form effectively increased ALP activity. In conclusion, it is suggested that these newly developed α-TCP/HAp beads are a promising tool for bone tissue engineering. Copyright © 2013 Wiley Periodicals, Inc.

  16. Applying a Hypoxia-Incorporating TCP Model to Experimental Data on Rat Sarcoma

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ruggieri, Ruggero, E-mail: ruggieri.ruggero@gmail.com; Stavreva, Nadejda; Naccarato, Stefania

    2012-08-01

    Purpose: To verify whether a tumor control probability (TCP) model which mechanistically incorporates acute and chronic hypoxia is able to describe animal in vivo dose-response data, exhibiting tumor reoxygenation. Methods and Materials: The investigated TCP model accounts for tumor repopulation, reoxygenation of chronic hypoxia, and fluctuating oxygenation of acute hypoxia. Using the maximum likelihood method, the model is fitted to Fischer-Moulder data on Wag/Rij rats, inoculated with rat rhabdomyosarcoma BA1112, and irradiated in vivo using different fractionation schemes. This data set is chosen because two of the experimental dose-response curves exhibit an inverse dose behavior, which is interpreted as duemore » to reoxygenation. The tested TCP model is complex, and therefore, in vivo cell survival data on the same BA1112 cell line from Reinhold were added to Fischer-Moulder data and fitted simultaneously with a corresponding cell survival function. Results: The obtained fit to the combined Fischer-Moulder-Reinhold data was statistically acceptable. The best-fit values of the model parameters for which information exists were in the range of published values. The cell survival curves of well-oxygenated and hypoxic cells, computed using the best-fit values of the radiosensitivities and the initial number of clonogens, were in good agreement with the corresponding in vitro and in situ experiments of Reinhold. The best-fit values of most of the hypoxia-related parameters were used to recompute the TCP for non-small cell lung cancer patients as a function of the number of fractions, TCP(n). Conclusions: The investigated TCP model adequately describes animal in vivo data exhibiting tumor reoxygenation. The TCP(n) curve computed for non-small cell lung cancer patients with the best-fit values of most of the hypoxia-related parameters confirms previously obtained abrupt reduction in TCP for n < 10, thus warning against the adoption of severely hypofractionated

  17. Efficacy of Honeycomb TCP-induced Microenvironment on Bone Tissue Regeneration in Craniofacial Area

    PubMed Central

    Watanabe, Satoko; Takabatake, Kiyofumi; Tsujigiwa, Hidetsugu; Watanabe, Toshiyuki; Tokuyama, Eijiro; Ito, Satoshi; Nagatsuka, Hitoshi; Kimata, Yoshihiro

    2016-01-01

    Artificial bone materials that exhibit high biocompatibility have been developed and are being widely used for bone tissue regeneration. However, there are no biomaterials that are minimally invasive and safe. In a previous study, we succeeded in developing honeycomb β-tricalcium phosphate (β-TCP) which has through-and-through holes and is able to mimic the bone microenvironment for bone tissue regeneration. In the present study, we investigated how the difference in hole-diameter of honeycomb β-TCP (hole-diameter: 75, 300, 500, and 1600 μm) influences bone tissue regeneration histologically. Its osteoconductivity was also evaluated by implantation into zygomatic bone defects in rats. The results showed that the maximum bone formation was observed on the β-TCP with hole-diameter 300μm, included bone marrow-like tissue and the pattern of bone tissue formation similar to host bone. Therefore, the results indicated that we could control bone tissue formation by creating a bone microenvironment provided by β-TCP. Also, in zygomatic bone defect model with honeycomb β-TCP, the result showed there was osseous union and the continuity was reproduced between the both edges of resected bone and β-TCP, which indicated the zygomatic bone reproduction fully succeeded. It is thus thought that honeycomb β-TCP may serve as an excellent biomaterial for bone tissue regeneration in the head, neck and face regions, expected in clinical applications. PMID:27279797

  18. Identification of Specific DNA Binding Residues in the TCP Family of Transcription Factors in Arabidopsis[W

    PubMed Central

    Aggarwal, Pooja; Das Gupta, Mainak; Joseph, Agnel Praveen; Chatterjee, Nirmalya; Srinivasan, N.; Nath, Utpal

    2010-01-01

    The TCP transcription factors control multiple developmental traits in diverse plant species. Members of this family share an ∼60-residue-long TCP domain that binds to DNA. The TCP domain is predicted to form a basic helix-loop-helix (bHLH) structure but shares little sequence similarity with canonical bHLH domain. This classifies the TCP domain as a novel class of DNA binding domain specific to the plant kingdom. Little is known about how the TCP domain interacts with its target DNA. We report biochemical characterization and DNA binding properties of a TCP member in Arabidopsis thaliana, TCP4. We have shown that the 58-residue domain of TCP4 is essential and sufficient for binding to DNA and possesses DNA binding parameters comparable to canonical bHLH proteins. Using a yeast-based random mutagenesis screen and site-directed mutants, we identified the residues important for DNA binding and dimer formation. Mutants defective in binding and dimerization failed to rescue the phenotype of an Arabidopsis line lacking the endogenous TCP4 activity. By combining structure prediction, functional characterization of the mutants, and molecular modeling, we suggest a possible DNA binding mechanism for this class of transcription factors. PMID:20363772

  19. Modulation of release kinetics by plasma polymerization of ampicillin-loaded β-TCP ceramics

    NASA Astrophysics Data System (ADS)

    Labay, C.; Buxadera-Palomero, J.; Avilés, M.; Canal, C.; Ginebra, M. P.

    2016-08-01

    Beta-tricalcium phosphate (β-TCP) bioceramics are employed in bone repair surgery. Their local implantation in bone defects puts them in the limelight as potential materials for local drug delivery. However, obtaining suitable release patterns fitting the required therapeutics is a challenge. Here, plasma polymerization of ampicillin-loaded β-TCP is studied for the design of a novel antibiotic delivery system. Polyethylene glycol-like (PEG-like) coating of β-TCP by low pressure plasma polymerization was performed using diglyme as precursor, and nanometric PEG-like layers were obtained by simple and double plasma polymerization processes. A significant increase in hydrophobicity, and the presence of plasma polymer was visible on the surface by SEM and quantified by XPS. As a main consequence of the plasma polymerisation, the release kinetics were successfully modified, avoiding burst release, and slowing down the initial rate of release leading to a 4.5 h delay in reaching the same antibiotic release percentage, whilst conservation of the activity of the antibiotic was simultaneously maintained. Thus, plasma polymerisation on the surface of bioceramics may be a good strategy to design controlled drug delivery matrices for local bone therapies.

  20. The Vibrio cholerae Minor Pilin TcpB Initiates Assembly and Retraction of the Toxin-Coregulated Pilus

    PubMed Central

    Harn, Tony; Spielman, Ingrid; Gao, Yang; Kovacikova, Gabriela; Biais, Nicolas

    2016-01-01

    Type IV pilus (T4P) systems are complex molecular machines that polymerize major pilin proteins into thin filaments displayed on bacterial surfaces. Pilus functions require rapid extension and depolymerization of the pilus, powered by the assembly and retraction ATPases, respectively. A set of low abundance minor pilins influences pilus dynamics by unknown mechanisms. The Vibrio cholerae toxin-coregulated pilus (TCP) is among the simplest of the T4P systems, having a single minor pilin TcpB and lacking a retraction ATPase. Here we show that TcpB, like its homolog CofB, initiates pilus assembly. TcpB co-localizes with the pili but at extremely low levels, equivalent to one subunit per pilus. We used a micropillars assay to demonstrate that TCP are retractile despite the absence of a retraction ATPase, and that retraction relies on TcpB, as a V. cholerae tcpB Glu5Val mutant is fully piliated but does not induce micropillars movements. This mutant is impaired in TCP-mediated autoagglutination and TcpF secretion, consistent with retraction being required for these functions. We propose that TcpB initiates pilus retraction by incorporating into the growing pilus in a Glu5-dependent manner, which stalls assembly and triggers processive disassembly. These results provide a framework for understanding filament dynamics in more complex T4P systems and the closely related Type II secretion system. PMID:27992883

  1. In vivo labeling of phencyclidine (PCP) receptors with sup 3 H-TCP in the mouse brain

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Maurice, T.; Vignon, J.

    1990-07-01

    The phencyclidine (PCP) derivative N-(1-(2-thienyl)cyclohexyl)-piperidine (3H-TCP) was used to label in vivo the N-methyl-D-aspartate (NMDA) receptor-associated ionic channel in the mouse brain. After the injection of a tracer dose of 3H-TCP, a spread labeling throughout the brain was observed, but was the highest in the cerebellum. Preadministration of unlabeled TCP (30 mg/kg) resulted in a 90% reduction of 3H-TCP binding. PCP, TCP, MK-801, dexoxadrol, ketamine, and SKF 10,047 isomers dose-dependently prevented the in vivo 3H-TCP binding. ID50 determined in the cerebrum and the cerebellum were respectively correlated with K0.5 for 3H TCP high (rat cortex) and low affinity (rat cerebellum)more » sites in vitro. The pharmacological specificity of the 3H-TCP binding site in the cerebellum was significantly different from that in the cerebrum. ID50 values were generally higher than in the cerebrum and, particularly, MK-801, the most potent drug in the cerebrum, was without significant effect in the cerebellum, at any time and at doses as high as 30 mg/kg. N-(1-(2-benzo(b) thiophenyl)cyclohexyl)piperidine (BTCP), desipramine, and atropine showed a more efficient prevention of 3H-TCP binding in the cerebellum than in the cerebrum. The prevention of the binding by TCP or PCP, at doses close to their ID50 values, was rapid and then decreased slowly. The effect of MK-801 was long-lasting. This study confirm previous in vitro studies: 3H-TCP is an efficient tool for the labeling of the NMDA receptor-associated ionic channel.« less

  2. In vitro study of 3D PLGA/n-HAp/β-TCP composite scaffolds with etched oxygen plasma surface modification in bone tissue engineering

    NASA Astrophysics Data System (ADS)

    Roh, Hee-Sang; Jung, Sang-Chul; Kook, Min-Suk; Kim, Byung-Hoon

    2016-12-01

    Three-dimensional (3D) scaffolds have many advantageous properties for bone tissue engineering application, due to its controllable properties such as pore size, structural shape and interconnectivity. In this study, effects on oxygen plasma surface modification and adding of nano-hydroxyapatite (n-HAp) and β-tricalcium phosphate (β-TCP) on the 3D PLGA/n-HAp/β-TCP scaffolds for improving preosteoblast cell (MC3T3-E1) adhesion, proliferation and differentiation were investigated. The 3D PLGA/n-HAp/β-TCP scaffolds were fabricated by 3D Bio-Extruder equipment. The 3D scaffolds were prepared with 0°/90° architecture and pore size of approximately 300 μm. In addition 3D scaffolds surface were etched by oxygen plasma to enhance the hydrophilic property and surface roughness. After oxygen plasma treatment, the surface chemistry and morphology were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, and atomic force microscopy. And also hydrophilic property was measured by contact angle. The MC3T3-E1 cell proliferation and differentiation were investigated by MTT assay and ALP activity. In present work, the 3D PLGA/HAp/beta-TCP composite scaffold with suitable structure for the growth of osteoblast cells was successfully fabricated by 3D rapid prototyping technique. The surface hydrophilicity and roughness of 3D scaffold increased by oxygen plasma treatment had a positive effect on cell adhesion, proliferation, and differentiation. Furthermore, the differentiation of MC3T3-E1 cell was significantly enhanced by adding of n-HAp and β-TCP on 3D PLGA scaffold. As a result, combination of bioceramics and oxygen plasma treatment showed a synergistic effect on biocompatibility of 3D scaffolds. This result confirms that this technique was useful tool for improving the biocompatibility in bone tissue engineering application.

  3. Enhancement of perfluoropolyether boundary lubrication performance: I. Preliminary results

    NASA Technical Reports Server (NTRS)

    Jones, W. R., Jr.; Ajayi, O. O.; Goodell, A. J.; Wedeven, L. D.; Devine, E.; Premore, R. E.

    1995-01-01

    A ball bearing simulator operating under starved conditions was used to evaluate the boundary lubrication performance of a perfluoropolyether (PFPE) Krytox 143 AB. Several approaches to enhance boundary lubrication were studied. These included: (1) soluble boundary additives, (2) bearing surface modifications, (3) 'run-in' surface films, and (4) ceramic bearing components. In addition, results were compared with two non-perfluorinated liquid lubricant formulations. Based on these preliminary tests, the following tentative conclusions can be made: (1) substantial improvements in boundary lubrication performance were observed with a beta-diketone boundary additive and a tricresyl phosphate (TCP) liquid surface pretreatment; (2) the use of rough Si3N4 balls (Ra = 40 micro-in) also provided substantial improvement but with concomitant abrasive wear; (3) marginal improvements were seen with two boundary additives (a phosphine and a phosphatriazine) and a neat (100%) fluid (a carboxylic acid terminated PFPE); and surface pretreatments with a synthetic hydrocarbon, a PTFE coating, and TiC coated 440C and smooth Si3N4 balls (R(sub a) less than 1 micro-in); and (4) two non-PFPE lubricant formulations (a PAO and a synthetic hydrocarbon) yielded substantial improvements.

  4. A Human Clinical, Histological, Histomorphometrical, and Radiographical Study on Biphasic HA-Beta-TCP 30/70 in Maxillary Sinus Augmentation.

    PubMed

    Mangano, Carlo; Sinjari, Bruna; Shibli, Jamil A; Mangano, Francesco; Hamisch, Sabine; Piattelli, Adriano; Perrotti, Vittoria; Iezzi, Giovanna

    2015-06-01

    By mixing hydroxyapatite (HA) and tricalcium phosphate (TCP), biphasic calcium phosphate ceramics can be obtained, and by varying their ratio it is possible to tailor the characteristics of the biomaterial. The aim of the present human study was to evaluate the histological and radiographical aspects of bone formation in maxillary sinus augmentation using a 30/70 HA-beta-TCP with a reticular structure. A total of 12 patients, undergoing two-stage sinus augmentation procedure using HA-beta-TCP at a ratio of 30/70, were included in the present study. After a 6-month healing period, during implant insertion, radiographical analysis was performed, and then the bone core biopsies were harvested and processed for histology. At radiographic evaluation, the bone gain was on average 6.85 ± 0.60 mm. HA-beta-TCP 30/70 appeared to be lined by newly formed bone, with no gaps at the interface. The histomorphometric analysis revealed 26 ± 2% of residual grafted biomaterial, 29 ± 3% of newly formed bone, and 45 ± 2% of marrow spaces. The present results indicate histologically the high biocompatibility and osteoconductivity of HA-beta-TCP 30/70, and clinically its successful use for sinus augmentation procedures. © 2013 Wiley Periodicals, Inc.

  5. Estimating TCP Packet Loss Ratio from Sampled ACK Packets

    NASA Astrophysics Data System (ADS)

    Yamasaki, Yasuhiro; Shimonishi, Hideyuki; Murase, Tutomu

    The advent of various quality-sensitive applications has greatly changed the requirements for IP network management and made the monitoring of individual traffic flows more important. Since the processing costs of per-flow quality monitoring are high, especially in high-speed backbone links, packet sampling techniques have been attracting considerable attention. Existing sampling techniques, such as those used in Sampled NetFlow and sFlow, however, focus on the monitoring of traffic volume, and there has been little discussion of the monitoring of such quality indexes as packet loss ratio. In this paper we propose a method for estimating, from sampled packets, packet loss ratios in individual TCP sessions. It detects packet loss events by monitoring duplicate ACK events raised by each TCP receiver. Because sampling reveals only a portion of the actual packet loss, the actual packet loss ratio is estimated statistically. Simulation results show that the proposed method can estimate the TCP packet loss ratio accurately from a 10% sampling of packets.

  6. A comparative study of proliferation and osteogenic differentiation of adipose-derived stem cells on akermanite and beta-TCP ceramics.

    PubMed

    Liu, Qihai; Cen, Lian; Yin, Shuo; Chen, Lei; Liu, Guangpeng; Chang, Jiang; Cui, Lei

    2008-12-01

    This study investigated the in vitro effects of akermanite, a new kind of Ca-, Mg-, Si-containing bioceramic, on the attachment, proliferation and osteogenic differentiation of human adipose-derived stem cells (hASCs). Parallel comparison of the cellular behaviors of hASCs on the akermanite was made with those on beta-tricalcium phosphate (beta-TCP). Scanning electron microscope (SEM) observation and fluorescent DiO labeling were carried out to reveal the attachment and growth of hASCs on the two ceramic surfaces, while the quantitative assay of cell proliferation with time was detected by DNA assay. Osteogenic differentiation of hASCs cultured on the akermanite and beta-TCP was assayed by ALP expression and osteocalcin (OCN) deposition, which was further confirmed by Real-time PCR analysis for markers of osteogenic differentiation. It was shown that hASCs attached and spread well on the akermanite as those on beta-TCP, and similar proliferation behaviors of hASCs were observed on the two ceramics. Both of them exhibited good compatibility to hASCs with only minor cytotoxicity as compared with the tissue culture plates. Interestingly, the osteogenic differentiation of hASCs could be enhanced on the akermanite compared with that on the beta-TCP when the culture time was extended to approximately 10 days. Thus, it can be ascertained that akermanite ceramics may serve as a potential scaffold for bone tissue engineering.

  7. ALP gene expression in cDNA samples from bone tissue engineering using a HA/TCP/Chitosan scaffold

    NASA Astrophysics Data System (ADS)

    Stephanie, N.; Katarina, H.; Amir, L. R.; Gunawan, H. A.

    2017-08-01

    This study examined the potential use of hydroxyapatite (HA)/tricalcium phosphate (TCP)/Chitosan as a bone tissue engineering scaffold. The potential for using HA/TCP/chitosan as a scaffold was analyzed by measuring expression of the ALP osteogenic gene in cDNA from bone biopsies from four Macaque nemestrina. Experimental conditions included control (untreated), treatment with HA/TCP 70:30, HA/TCP 50:50, and HA/TCP/chitosan. cDNA samples were measured quantitively with Real-Time PCR (qPCR) and semi-quantitively by gel electrophoresis. There were no significant differences in ALP gene expression between treatment subjects after two weeks, but the HA/TCP/chitosan treatment gave the highest level of expression after four weeks. The scaffold using the HA/TCP/chitosan combination induced a higher level of expression of the osteogenic gene ALP than did scaffold without chitosan.

  8. The Arabidopsis thaliana TCP transcription factors: A broadening horizon beyond development

    PubMed Central

    Li, Shutian

    2015-01-01

    The TCP family of transcription factors is named after the first 4 characterized members, namely TEOSINTE BRANCHED1 (TB1) from maize (Zea mays), CYCLOIDEA (CYC) from snapdragon (Antirrhinum majus), as well as PROLIFERATING CELL NUCLEAR ANTIGEN FACTOR1 (PCF1) and PCF2 from rice (Oryza sativa). Phylogenic analysis of this plant-specific protein family unveils a conserved bHLH-containing DNA-binding motif known as the TCP domain. In accordance with the structure of this shared domain, TCP proteins are grouped into class I (TCP-P) and class II (TCP-C), which are suggested to antagonistically modulate plant growth and development via competitively binding similar cis-regulatory modules called site II elements. Over the last decades, TCPs across the plant kingdom have been demonstrated to control a plethora of plant processes. Notably, TCPs also regulate plant development and defense responses via stimulating the biosynthetic pathways of bioactive metabolites, such as brassinosteroid (BR), jasmonic acid (JA) and flavonoids. Besides, mutagenesis analysis coupled with biochemical experiments identifies several crucial amino acids located within the TCP domain, which confer the redox sensitivity of class I TCPs and determine the distinct DNA-binding properties of TCPs. In this review, developmental functions of TCPs in various biological pathways are briefly described with an emphasis on their involvement in the synthesis of bioactive substances. Furthermore, novel biochemical aspects of TCPs with respect to redox regulation and DNA-binding preferences are elaborated. In addition, the unexpected participation of TCPs in effector-triggered immunity (ETI) and defense against insects indicates that the widely recognized developmental regulators are capable of fine-tuning defense signaling and thereby enable plants to evade deleterious developmental phenotypes. Altogether, these recent impressive breakthroughs remarkably advance our understanding as to how TCPs integrate

  9. The Arabidopsis thaliana TCP transcription factors: A broadening horizon beyond development.

    PubMed

    Li, Shutian

    2015-01-01

    The TCP family of transcription factors is named after the first 4 characterized members, namely TEOSINTE BRANCHED1 (TB1) from maize (Zea mays), CYCLOIDEA (CYC) from snapdragon (Antirrhinum majus), as well as PROLIFERATING CELL NUCLEAR ANTIGEN FACTOR1 (PCF1) and PCF2 from rice (Oryza sativa). Phylogenic analysis of this plant-specific protein family unveils a conserved bHLH-containing DNA-binding motif known as the TCP domain. In accordance with the structure of this shared domain, TCP proteins are grouped into class I (TCP-P) and class II (TCP-C), which are suggested to antagonistically modulate plant growth and development via competitively binding similar cis-regulatory modules called site II elements. Over the last decades, TCPs across the plant kingdom have been demonstrated to control a plethora of plant processes. Notably, TCPs also regulate plant development and defense responses via stimulating the biosynthetic pathways of bioactive metabolites, such as brassinosteroid (BR), jasmonic acid (JA) and flavonoids. Besides, mutagenesis analysis coupled with biochemical experiments identifies several crucial amino acids located within the TCP domain, which confer the redox sensitivity of class I TCPs and determine the distinct DNA-binding properties of TCPs. In this review, developmental functions of TCPs in various biological pathways are briefly described with an emphasis on their involvement in the synthesis of bioactive substances. Furthermore, novel biochemical aspects of TCPs with respect to redox regulation and DNA-binding preferences are elaborated. In addition, the unexpected participation of TCPs in effector-triggered immunity (ETI) and defense against insects indicates that the widely recognized developmental regulators are capable of fine-tuning defense signaling and thereby enable plants to evade deleterious developmental phenotypes. Altogether, these recent impressive breakthroughs remarkably advance our understanding as to how TCPs integrate

  10. Comparative Efficacies of Collagen-Based 3D Printed PCL/PLGA/β-TCP Composite Block Bone Grafts and Biphasic Calcium Phosphate Bone Substitute for Bone Regeneration.

    PubMed

    Hwang, Kyoung-Sub; Choi, Jae-Won; Kim, Jae-Hun; Chung, Ho Yun; Jin, Songwan; Shim, Jin-Hyung; Yun, Won-Soo; Jeong, Chang-Mo; Huh, Jung-Bo

    2017-04-17

    The purpose of this study was to compare bone regeneration and space maintaining ability of three-dimensional (3D) printed bone grafts with conventional biphasic calcium phosphate (BCP). After mixing polycaprolactone (PCL), poly (lactic-co-glycolic acid) (PLGA), and β-tricalcium phosphate (β-TCP) in a 4:4:2 ratio, PCL/PLGA/β-TCP particulate bone grafts were fabricated using 3D printing technology. Fabricated particulate bone grafts were mixed with atelocollagen to produce collagen-based PCL/PLGA/β-TCP composite block bone grafts. After formation of calvarial defects 8 mm in diameter, PCL/PLGA/β-TCP composite block bone grafts and BCP were implanted into bone defects of 32 rats. Although PCL/PLGA/β-TCP composite block bone grafts were not superior in bone regeneration ability compared to BCP, the results showed relatively similar performance. Furthermore, PCL/PLGA/β-TCP composite block bone grafts showed better ability to maintain bone defects and to support barrier membranes than BCP. Therefore, within the limitations of this study, PCL/PLGA/β-TCP composite block bone grafts could be considered as an alternative to synthetic bone grafts available for clinical use.

  11. Soybean TCP transcription factors: Evolution, classification, protein interaction and stress and hormone responsiveness.

    PubMed

    Feng, Zhi-Juan; Xu, Sheng-Chun; Liu, Na; Zhang, Gu-Wen; Hu, Qi-Zan; Gong, Ya-Ming

    2018-06-01

    TEOSINTE-BRANCHED1/CYCLOIDEA/PCF (TCP) transcription factors, a family of plant-specific proteins, play crucial roles in plant growth and development and stress response. However, systematical information is unknown regarding the TCP gene family in soybean. In the present study, a total of 54 GmTCPs were identified in soybean, which were grouped into 11 groups with the typical TCP conserved domains. Phylogenetic relationship, protein motif and gene structure analyses distinguished the GmTCPs into two homology classes: Class I and Class II. Class II was then differentiated into two subclasses: CIN and CYC/TB1. Unique cis-element number and composition existed in the promoter regions which might be involved in the gene transcriptional regulation of different GmTCPs. Tissue expression analysis demonstrated the diverse spatiotemporal expression profiles of GmTCPs. Furthermore, the interaction protein of one previously functionally unknown TCP protein-GmTCP8 was investigated. Yeast two-hybrid assay showed the interaction between GmTCP8 and an abscisic acid receptor (GmPYL10). QRT-PCR assays indicated the distinct expression profiles of GmTCPs in response to abiotic stresses (heat, drought and salt) and stress-related signals (abscisic acid, brassinolide, salicylicacid and methyl jasmonate). These results will facilitate to uncover the possible roles of GmTCPs under abiotic stress and hormone signal responses in soybean. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  12. Effect of Alendronate with β - TCP Bone Substitute in Surgical Therapy of Periodontal Intra-Osseous Defects: A Randomized Controlled Clinical Trial.

    PubMed

    Naineni, Rohini; Ravi, Vishali; Subbaraya, Dwijendra Kocherlakota; Prasanna, Jammula Surya; Panthula, Veerendranath Reddy; Koduganti, Rekha Rani

    2016-08-01

    Alendronate (ALN), an aminobisphosphonate, inhibits osteoclastic bone resorption and also stimulates osteogenesis. Beta-Tricalcium Phosphate (β-TCP) is an osteoconductive graft material which provides a scaffold for bone formation and also a widely used drug delivery vehicle for growth factors and antibiotics. Drug delivery vehicles, like β-TCP, improve the potency of the drugs by specific local site delivery of the drug, optimal release characteristics and easy handling. The aim of the this study was to evaluate the bone formation potential of 400μg ALN delivered in β-TCP in the treatment of periodontal intra-osseous defects. Thirty patients with periodontal defects were randomly assigned to 400μg ALN + β-TCP + Saline (test) group and β-TCP + Saline (active-control) group. Clinical parameters like Clinical Attachment Level (CAL) gain, Probing Depth (PD) reduction, post-operative Gingival Recession (GR) were assessed from the baseline, 3 months and 6 months recordings. Radiographic parameters like Linear Bone Growth (LBG), Percentage Bone Fill (%BF), and change in alveolar crest height (ACH) were assessed from baseline and 6 months radiographs. Mean measurements in the ALN test group for CAL gain (3.4 ± 0.74 mm), PD reduction (4.33 ± 0.82 mm), LBG (2.88 ± 0.88 mm), and %BF (51.98 ± 15.84%) were significantly greater with a p-value <0.05 compared to the mean measurements of CAL gain (2.20 ± 0.86 mm), PD reduction (3.20 ± 1.15 mm), LBG (1.70 ± 0.39 mm), and %BF (30.35 ± 6.88%) of the control group. There was mild alveolar crestal apposition (0.32 ± 0.68 mm) in the ALN test group and mild alveolar crestal resorption (-0.24 ± 0.40 mm) in the control group. 400μg ALN combined with β-TCP bone graft material was effective in improving soft tissue parameters, inhibiting alveolar crestal resorption and enhancing bone formation, compared to β-TCP alone.

  13. Application of stochastic discrete event system framework for detection of induced low rate TCP attack.

    PubMed

    Barbhuiya, F A; Agarwal, Mayank; Purwar, Sanketh; Biswas, Santosh; Nandi, Sukumar

    2015-09-01

    TCP is the most widely accepted transport layer protocol. The major emphasis during the development of TCP was its functionality and efficiency. However, not much consideration was given on studying the possibility of attackers exploiting the protocol, which has lead to several attacks on TCP. This paper deals with the induced low rate TCP attack. Since the attack is relatively new, only a few schemes have been proposed to mitigate it. However, the main issues with these schemes are scalability, change in TCP header, lack of formal frameworks, etc. In this paper, we have adapted the stochastic DES framework for detecting the attack, which addresses most of these issues. We have successfully deployed and tested the proposed DES based IDS on a test bed. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  14. The Arabidopsis transcription factor AtTCP15 regulates endoreduplication by modulating expression of key cell-cycle genes.

    PubMed

    Li, Zi-Yu; Li, Bin; Dong, Ai-Wu

    2012-01-01

    Plant cells frequently undergo endoreduplication, a modified cell cycle in which genome is repeatedly replicated without cytokinesis. As the key step to achieve final size and function for cells, endoreduplication is prevalent during plant development. However, mechanisms to control the balance between endoreduplication and mitotic cell division are still poorly understood. Here, we show that the Arabidopsis TCP (CINCINNATA-like TEOSINTE BRANCHED1-CYCLOIDEA-PCF)-family transcription factor gene AtTCP15 is expressed in trichomes, as well as in rapidly dividing and vascular tissues. Expression of AtTCP15SRDX, AtTCP15 fused with a SRDX repressor domain, induces extra endoreduplication in trichomes and cotyledon cells in transgenic Arabidopsis. On the contrary, overexpression of AtTCP15 suppresses endoreduplication in trichomes and other examined cells. Misregulation of AtTCP15 affects the expression of several important genes involved in cell-cycle regulation. AtTCP15 protein binds directly to the promoter regions of CYCA2;3 and RETINOBLASTOMA-RELATED (RBR) genes, which play key roles in endoreduplication. Taken together, AtTCP15 plays an important role in regulating endoreduplication during Arabidopsis development.

  15. The TCP4 transcription factor of Arabidopsis blocks cell division in yeast at G1 {yields} S transition

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Aggarwal, Pooja; Padmanabhan, Bhavna; Bhat, Abhay

    2011-07-01

    Highlights: {yields} TCP4 is a class II TCP transcription factor, that represses cell division in Arabidopsis. {yields} TCP4 expression in yeast retards cell division by blocking G1 {yields} S transition. {yields} Genome-wide expression studies and Western analysis reveals stabilization of cell cycle inhibitor Sic1, as possible mechanism. -- Abstract: The TCP transcription factors control important aspects of plant development. Members of class I TCP proteins promote cell cycle by regulating genes directly involved in cell proliferation. In contrast, members of class II TCP proteins repress cell division. While it has been postulated that class II proteins induce differentiation signal, theirmore » exact role on cell cycle has not been studied. Here, we report that TCP4, a class II TCP protein from Arabidopsis that repress cell proliferation in developing leaves, inhibits cell division by blocking G1 {yields} S transition in budding yeast. Cells expressing TCP4 protein with increased transcriptional activity fail to progress beyond G1 phase. By analyzing global transcriptional status of these cells, we show that expression of a number of cell cycle genes is altered. The possible mechanism of G1 {yields} S arrest is discussed.« less

  16. Analysis of the TCP genes expressed in the inflorescence of the orchid Orchis italica

    PubMed Central

    De Paolo, Sofia; Gaudio, Luciano; Aceto, Serena

    2015-01-01

    TCP proteins are plant-specific transcription factors involved in many different processes. Because of their involvement in a large number of developmental pathways, their roles have been investigated in various plant species. However, there are almost no studies of this transcription factor family in orchids. Based on the available transcriptome of the inflorescence of the orchid Orchis italica, in the present study we identified 12 transcripts encoding TCP proteins. The phylogenetic analysis showed that they belong to different TCP classes (I and II) and groups (PCF, CIN and CYC/TB1), and that they display a number of conserved motifs when compared with the TCPs of Arabidopsis and Oryza. The presence of a specific cleavage site for the microRNA miRNA319, an important post-transcriptional regulator of several TCP genes in other species, was demonstrated for one transcript of O. italica, and the analysis of the expression pattern of the TCP transcripts in different inflorescence organs and in leaf tissue suggests that some TCP transcripts of O. italica exert their role only in specific tissues, while others may play multiple roles in different tissues. In addition, the evolutionary analysis showed a general purifying selection acting on the coding region of these transcripts. PMID:26531864

  17. Analysis of the TCP genes expressed in the inflorescence of the orchid Orchis italica.

    PubMed

    De Paolo, Sofia; Gaudio, Luciano; Aceto, Serena

    2015-11-04

    TCP proteins are plant-specific transcription factors involved in many different processes. Because of their involvement in a large number of developmental pathways, their roles have been investigated in various plant species. However, there are almost no studies of this transcription factor family in orchids. Based on the available transcriptome of the inflorescence of the orchid Orchis italica, in the present study we identified 12 transcripts encoding TCP proteins. The phylogenetic analysis showed that they belong to different TCP classes (I and II) and groups (PCF, CIN and CYC/TB1), and that they display a number of conserved motifs when compared with the TCPs of Arabidopsis and Oryza. The presence of a specific cleavage site for the microRNA miRNA319, an important post-transcriptional regulator of several TCP genes in other species, was demonstrated for one transcript of O. italica, and the analysis of the expression pattern of the TCP transcripts in different inflorescence organs and in leaf tissue suggests that some TCP transcripts of O. italica exert their role only in specific tissues, while others may play multiple roles in different tissues. In addition, the evolutionary analysis showed a general purifying selection acting on the coding region of these transcripts.

  18. Biological optimization of simultaneous boost on intra-prostatic lesions (DILs): sensitivity to TCP parameters.

    PubMed

    Azzeroni, R; Maggio, A; Fiorino, C; Mangili, P; Cozzarini, C; De Cobelli, F; Di Muzio, N G; Calandrino, R

    2013-11-01

    The aim of this investigation was to explore the potential of biological optimization in the case of simultaneous integrated boost on intra-prostatic dominant lesions (DIL) and evaluating the impact of TCP parameters uncertainty. Different combination of TCP parameters (TD50 and γ50 in the Poisson-like model), were considered for DILs and the prostate outside DILs (CTV) for 7 intermediate/high-risk prostate patients. The aim was to maximize TCP while constraining NTCPs below 5% for all organs at risk. TCP values were highly depending on the parameters used and ranged between 38.4% and 99.9%; the optimized median physical doses were in the range 94-116 Gy and 69-77 Gy for DIL and CTV respectively. TCP values were correlated with the overlap PTV-rectum and the minimum distance between rectum and DIL. In conclusion, biological optimization for selective dose escalation is feasible and suggests prescribed dose around 90-120 Gy to the DILs. The obtained result is critically depending on the assumptions concerning the higher radioresistence in the DILs. In case of very resistant clonogens into the DIL, it may be difficult to maximize TCP to acceptable levels without violating NTCP constraints. Copyright © 2012 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  19. Research of osteoblastic induced rat bone marrow mesenchymal stem cells cultured on β-TCP/PLLA porous scaffold.

    PubMed

    Yang, Yi; Wu, Jiang; Jin, Gele; Li, Liang; Li, Zhongwei; Li, Cao

    2015-01-01

    Ceramic and polymer composite scaffolds are widely used in tissue engineering for bone tissue regeneration. Composite of β-tricalcium phosphate (β-TCP) and poly L-lactic acid (PLLA), due to its biocompatibility and biodegradability, is widely used in bioengineering. However, optimal ratio, porosity and pore size of this kind of scaffolds were not very clear yet. We cultured osteoblastic induced rMSCs on β-TCP/PLLA scaffolds to investigate the optimum construction, which owned better properties for supporting cells growth, proliferation and differentiation. A total of 24 mice were divided into three groups: rMSCs + β-TCP/PLLA, osteoblastic rMSCs + β-TCP/PLLA and β-TCP/PLLA without cells. 8 rude mice were implanted with rMSCs + β-TCP/PLLA in the left thighs and β-TCP/PLLA without cells in the right thighs. 8 rude mice were implanted with osteoblastic rMSCs + β-TCP/PLLA in the left thighs and the same treatments in the right thighs as the above. After 8 and 12 weeks, the mice were sacrificed and implants with the surrounding tissues were harvested together. Paraffin sections were got and HE stain and Masson-Goldner stain were employed to observe the ectopic bone formation. The scaffolds of β-TCP/PLLA = 2:1 significantly increased osteocalcin production of the cells. In addition, scaffolds with NaCl = 70 wt%, pore size 200~450 μm showed better compatibility to these seeding cells. A significantly larger area of bone formation in the osteoblastic rMSCs and β-TCP/PLLA composite than that in rMSCs/scaffold and in the scaffold without cells in vivo. compounds of osteoblastic induced rMSCs and the scaffold with β-TCP/PLLA = 2:1, NaCl = 70 wt%, pore size = 200-450 μm had good properties as a kind of bone substitute.

  20. Effect of amorphous phases during the hydraulic conversion of α-TCP into calcium-deficient hydroxyapatite.

    PubMed

    Hurle, Katrin; Neubauer, Juergen; Bohner, Marc; Doebelin, Nicola; Goetz-Neunhoeffer, Friedlinde

    2014-09-01

    Powders of α-tricalcium phosphate (α-TCP), which readily react with water to form calcium-deficient hydroxyapatite (CDHA), are frequently used in bone cements. As, for clinical applications, it is important to adjust the setting reaction of the cements to a reasonable reaction time, exact knowledge of the hydration mechanism is essential. It is known that prolonged milling results in partial amorphization of α-TCP powders and that dissolution of the amorphous phase significantly accelerates the hydration, but it is not clear yet when the amorphous phase reacts in comparison to the crystalline α-TCP. Therefore the aim of this study was to investigate the development of quantitative phase content of α-TCP samples during hydration. For this purpose, three α-TCP powders, containing 0, 16 and 71wt.% of amorphous phase (ATCP), were mixed with either deionized water or a 0.1M Na2HPO4 aqueous solution. The crystalline evolution of the paste was assessed quantitatively during the first 48h of hydration at 23°C by G-factor quantification. The present investigations demonstrate that ATCP reacted earlier than crystalline α-TCP. The results also suggest the formation of an X-ray amorphous phase during the hydraulic conversion formation of α-TCP into CDHA. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  1. A new Grid Product of Tropical Cyclone Precipitation (TCP) for North America from 1930 to 2013

    NASA Astrophysics Data System (ADS)

    Zhu, L.

    2015-12-01

    We first developed a new method that collects daily TCP by using historical storm tracks and precipitation observation based on daily rain gauges in both U.S. and Mexico and calibrated it with satellite precipitation observation. We used a parametrized wind field to correct the possible under-estimations of precipitation in rain gauges. Grid interpolation parameters were optimized by testing different historical rain gauge densities and comparing our grid estimation of TCP and the observation from TRMM Multi-satellite Precipitation Analysis (3B42) by for the data available period from 1998 to 2013. The calibrated method was then used for the whole 94 years of TCP estimation. The preliminary result shows that the frequency of TCP events does not have significant change but the TCP intensity has significant increasing trends, especially in certain locations in North Carolina and Yucatan Peninsula in Mexico. This new long term TCP climatology can potentially assist model calibration and disaster prevention/mitigation.

  2. Running TCP/IP over ATM Networks.

    ERIC Educational Resources Information Center

    Witt, Michael

    1995-01-01

    Discusses Internet protocol (IP) and subnets and describes how IP may operate over asynchronous transfer mode (ATM). Topics include TCP (transmission control protocol), ATM cells and adaptation layers, a basic architectural model for IP over ATM, address resolution, mapping IP to a subnet technology, and connection management strategy. (LRW)

  3. The Arabidopsis immune adaptor SRFR1 interacts with TCP transcription factors that redundantly contribute to effector-triggered immunity.

    PubMed

    Kim, Sang Hee; Son, Geon Hui; Bhattacharjee, Saikat; Kim, Hye Jin; Nam, Ji Chul; Nguyen, Phuong Dung T; Hong, Jong Chan; Gassmann, Walter

    2014-06-01

    The plant immune system must be tightly controlled both positively and negatively to maintain normal plant growth and health. We previously identified SUPPRESSOR OF rps4-RLD1 (SRFR1) as a negative regulator specifically of effector-triggered immunity. SRFR1 is localized in both a cytoplasmic microsomal compartment and in the nucleus. Its TPR domain has sequence similarity to TPR domains of transcriptional repressors in other organisms, suggesting that SRFR1 may negatively regulate effector-triggered immunity via transcriptional control. We show here that excluding SRFR1 from the nucleus prevented complementation of the srfr1 phenotype. To identify transcription factors that interact with SRFR1, we screened an Arabidopsis transcription factor prey library by yeast two-hybrid assay and isolated six class I members of the TEOSINTE BRANCHED1/CYCLOIDEA/PCF (TCP) transcription factor family. Specific interactions were verified in planta. Although single or double T-DNA mutant tcp8, tcp14 or tcp15 lines were not more susceptible to bacteria expressing AvrRps4, the triple tcp8 tcp14 tcp15 mutant displayed decreased effector-triggered immunity mediated by the resistance genes RPS2, RPS4, RPS6 and RPM1. In addition, expression of PATHOGENESIS-RELATED PROTEIN2 was attenuated in srfr1-4 tcp8-1 tcp14-5 tcp15-3 plants compared to srfr1-4 plants. To date, TCP transcription factors have been implicated mostly in developmental processes. Our data indicate that one function of a subset of TCP proteins is to regulate defense gene expression in antagonism to SRFR1, and suggest a mechanism for an intimate connection between plant development and immunity. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  4. β-TCP porous pellets as an orthopaedic drug delivery system: ibuprofen/carrier physicochemical interactions

    NASA Astrophysics Data System (ADS)

    Baradari, Hiba; Damia, Chantal; Dutreih-Colas, Maggy; Champion, Eric; Chulia, Dominique; Viana, Marylène

    2011-10-01

    Calcium phosphate bone substitute materials can be loaded with active substances for in situ, targeted drug administration. In this study, porous β-TCP pellets were investigated as an anti-inflammatory drug carrier. Porous β-TCP pellets were impregnated with an ethanolic solution of ibuprofen. The effects of contact time and concentration of ibuprofen solution on drug adsorption were studied. The ibuprofen adsorption equilibrium time was found to be one hour. The adsorption isotherms fitted to the Freundlich model, suggesting that the interaction between ibuprofen and β-TCP is weak. The physicochemical characterizations of loaded pellets confirmed that the reversible physisorption of ibuprofen on β-TCP pellets is due to Van der Waals forces, and this property was associated with the 100% ibuprofen release.

  5. Immunohistochemical response in rats of beta-tricalcium phosphate (TCP) with or without BMP-2 in the production of collagen matrix critical defects.

    PubMed

    Luvizuto, Eloá Rodrigues; de Oliveira, Júlio César Silva; Gomes-Ferreira, Pedro Henrique Silva; Pereira, Cassiano Costa Silva; Faverani, Leonardo Perez; Antoniali, Cristina; Okamoto, Roberta

    2017-04-01

    This study aimed to assess the biological response of BMP-2 (bone morphogenetic protein-2) in supplementation with β-tricalcium phosphate (TCP) as a carrier in the bone healing of surgical defects in rats' calvaria. A critical-size defect (5mm in diameter) was filled with β-TCP alone or added with that plus 5mg of BMP-2 at 5, 15, and 30 postoperative days. Histomorphometric and immunohistochemical (osteocalcin, collagen type I, and metalloproteinase-9) analysis was performed to assess the features of bone healing. Histological behavior and collagen type I labeling showed increased formation of the collagen matrix, leading to a higher percentage of newly formed bone and biomaterial for tissue and more total mineralization of pure TCP when compared to the other groups. The supplementation with BMP-2 promoted faster TCP remodeling; however, there was no statistically significant difference for the bone formed in both groups (P>0.05). Collagen-matrix formation and new bone formation reached maximum levels when the defects were filled with pure TCP, even exceeding the levels from BMP-2 supplementation. Copyright © 2017 Elsevier GmbH. All rights reserved.

  6. Degradation of 1,2,3-trichloropropane (TCP): hydrolysis, elimination, and reduction by iron and zinc.

    PubMed

    Sarathy, Vaishnavi; Salter, Alexandra J; Nurmi, James T; O'Brien Johnson, Graham; Johnson, Richard L; Tratnyek, Paul G

    2010-01-15

    1,2,3-Trichloropropane (TCP) is an emerging contaminant because of increased recognition of its occurrence in groundwater, potential carcinogenicity, and resistance to natural attenuation. The physical and chemical properties of TCP make it difficult to remediate, with all conventional options being relatively slow or inefficient. Treatments that result in alkaline conditions (e.g., permeable reactive barriers containing zerovalent iron) favor base-catalyzed hydrolysis of TCP, but high temperature (e.g., conditions of in situ thermal remediation) is necessary for this reaction to be significant. Common reductants (sulfide, ferrous iron adsorbed to iron oxides, and most forms of construction-grade or nano-Fe(0)) produce insignificant rates of reductive dechlorination of TCP. Quantifiable rates of TCP reduction were obtained with several types of activated nano-Fe(0), but the surface area normalized rate contants (k(SA)) for these reactions were lower than is generally considered useful for in situ remediation applications (10(-4) L m(-2) h(-1)). Much faster rates of degradation of TCP were obtained with granular Zn(0), (k(SA) = 10(-3) - 10(-2) L m(-2) h(-1)) and potentially problematic dechlorination intermediates (1,2- or 1,3-dichloropropane, 3-chloro-1-propene) were not detected. The advantages of Zn(0) over Fe(0) are somewhat peculiar to TCP and may suggest a practical application for Zn(0) even though it has not found favor for remediation of contamination with other chlorinated solvents.

  7. Osteointegration of PLGA implants with nanostructured or microsized β-TCP particles in a minipig model.

    PubMed

    Kulkova, Julia; Moritz, Niko; Suokas, Esa O; Strandberg, Niko; Leino, Kari A; Laitio, Timo T; Aro, Hannu T

    2014-12-01

    Bioresorbable suture anchors and interference screws have certain benefits over equivalent titanium-alloy implants. However, there is a need for compositional improvement of currently used bioresorbable implants. We hypothesized that implants made of poly(l-lactide-co-glycolide) (PLGA) compounded with nanostructured particles of beta-tricalcium phosphate (β-TCP) would induce stronger osteointegration than implants made of PLGA compounded with microsized β-TCP particles. The experimental nanostructured self-reinforced PLGA (85L:15G)/β-TCP composite was made by high-energy ball-milling. Self-reinforced microsized PLGA (95L:5G)/β-TCP composite was prepared by melt-compounding. The composites were characterized by gas chromatography, Ubbelohde viscometry, scanning electron microscopy, laser diffractometry, and standard mechanical tests. Four groups of implants were prepared for the controlled laboratory study employing a minipig animal model. Implants in the first two groups were prepared from nanostructured and microsized PLGA/β-TCP composites respectively. Microroughened titanium-alloy (Ti6Al4V) implants served as positive intra-animal control, and pure PLGA implants as negative control. Cone-shaped implants were inserted in a random order unilaterally in the anterior cortex of the femoral shaft. Eight weeks after surgery, the mechanical strength of osteointegration of the implants was measured by a push-out test. The quality of new bone surrounding the implant was assessed by microcomputed tomography and histology. Implants made of nanostructured PLGA/β-TCP composite did not show improved mechanical osteointegration compared with the implants made of microsized PLGA/β-TCP composite. In the intra-animal comparison, the push-out force of two PLGA/β-TCP composites was 35-60% of that obtained with Ti6Al4V implants. The implant materials did not result in distinct differences in quality of new bone surrounding the implant. Copyright © 2014 Elsevier Ltd. All

  8. Interacting TCP and NLP transcription factors control plant responses to nitrate availability.

    PubMed

    Guan, Peizhu; Ripoll, Juan-José; Wang, Renhou; Vuong, Lam; Bailey-Steinitz, Lindsay J; Ye, Dening; Crawford, Nigel M

    2017-02-28

    Plants have evolved adaptive strategies that involve transcriptional networks to cope with and survive environmental challenges. Key transcriptional regulators that mediate responses to environmental fluctuations in nitrate have been identified; however, little is known about how these regulators interact to orchestrate nitrogen (N) responses and cell-cycle regulation. Here we report that teosinte branched1/cycloidea/proliferating cell factor1-20 (TCP20) and NIN-like protein (NLP) transcription factors NLP6 and NLP7, which act as activators of nitrate assimilatory genes, bind to adjacent sites in the upstream promoter region of the nitrate reductase gene, NIA1 , and physically interact under continuous nitrate and N-starvation conditions. Regions of these proteins necessary for these interactions were found to include the type I/II Phox and Bem1p (PB1) domains of NLP6&7, a protein-interaction module conserved in animals for nutrient signaling, and the histidine- and glutamine-rich domain of TCP20, which is conserved across plant species. Under N starvation, TCP20-NLP6&7 heterodimers accumulate in the nucleus, and this coincides with TCP20 and NLP6&7-dependent up-regulation of nitrate assimilation and signaling genes and down-regulation of the G 2 /M cell-cycle marker gene, CYCB1;1 TCP20 and NLP6&7 also support root meristem growth under N starvation. These findings provide insights into how plants coordinate responses to nitrate availability, linking nitrate assimilation and signaling with cell-cycle progression.

  9. The effect of Tricresyl-Phosphate (TCP) as an additive on wear of Iron (Fe)

    NASA Technical Reports Server (NTRS)

    Ghose, Hiren M.; Ferrante, John; Honecy, Frank C.

    1987-01-01

    The effect of tricresyl phosphate (TCP) as an antiwear additive in lubricant trimethyol propane triheptanoate (TMPTH) was investigated. The objective was to examine step loading wear by use of surface analysis, wetting, and chemical bonding changes in the lubricant. The investigation consisted of steploading wear studies by a pin or disk tribometer, the effects on wear related to wetting by contact angle and surface tension measurements of various liquid systems, the chemical bonding changes between lubricant and TCP chromatographic analysis, and by determining the reaction between the TCP and metal surfaces through wear scar analysis by Auger emission spectroscopy (AES). The steploading curve for the base fluid alone shows rapid increase of wear rate with load. The steploading curve for the base fluid in presence of 4.25 percent by volume TCP under dry air purge has shown a great reduction of wear rate with all loads studied. It has also been found that the addition of 4.25 percent by volume TCP plus 0.33 percent by volume water to the base lubricant under N2 purge also greatly reduces the wear rate with all loads studied. AES surface analysis reveals a phosphate type wear resistant film, which greatly increases load-bearing capacity, formed on the iron disk. Preliminary chromatographic studies suggest that this film forms either because of ester oxidation or TCP degradation. Wetting studies show direct correlation between the spreading coefficient and the wear rate.

  10. The application of PRP combined with TCP in repairing avascular necrosis of the femoral head after femoral neck fracture in rabbit.

    PubMed

    Zhang, X-L; Wang, Y-M; Chu, K; Wang, Z-H; Liu, Y-H; Jiang, L-H; Chen, X; Zhou, Z-Y; Yin, G

    2018-02-01

    In view of the high occurrence of avascular necrosis of the femoral head (ANFH) after femoral neck fracture and the difficulties in the treatment, our work aimed to explore the effects of platelet-rich plasma (PRP) combined with tri-calcium phosphate (TCP) on the repair of ANFH after femoral neck fracture and to provide reference for clinical treatment. Thirty New Zealand white rabbits were randomly divided into control group, TCP group, and PRP+TCP group. The rabbit ANFH model was established and femoral head tissues were collected. HE staining was used for histological observation. Image analysis and statistical analysis were used to calculate the New Bone Area fraction (NBA %). The levels of bone morphogenetic protein (BMP)-7, transforming growth factor (TGF)-β1, basic fibroblast growth factor (bFGF), interleukin (IL)-6 and tumor necrosis factor (TNF)-a in serum were detected by Enzyme-Linked ImmunoSorbent Assay (ELISA). The new bone area of TCP group was significantly lower than that of PRP+TCP group (p<0.05). Compared with the control group, the levels of BMP-7, TGF-β1 and bFGF were significantly increased in both TCP and PRP+TCP groups (p<0.05), and the increase in PRP+TCP group was higher than that in TCP group. TCP and PRP+TCP can both significantly reduce the content of IL-6 and TNF-a (p<0.05); however, higher decrease was found in PRP+TCP group compared with the TCP group at 8 weeks after injection. PRP combined with TCP, which can promote new bone formation and inhibit inflammatory response, showed higher efficiency in repairing ANFH than internal fixation alone.

  11. Roles of miR319 and TCP Transcription Factors in Leaf Development.

    PubMed

    Koyama, Tomotsugu; Sato, Fumihiko; Ohme-Takagi, Masaru

    2017-10-01

    Sophisticated regulation of gene expression, including microRNAs (miRNAs) and their target genes, is required for leaf differentiation, growth, and senescence. The impact of miR319 and its target TEOSINTE BRANCHED1 , CYCLOIDEA , and PROLIFERATING CELL NUCLEAR ANTIGEN BINDING FACTOR ( TCP ) genes on leaf development has been extensively investigated, but the redundancies of these gene families often interfere with the evaluation of their function and regulation in the developmental context. Here, we present the genetic evidence of the involvement of the MIR319 and TCP gene families in Arabidopsis ( Arabidopsis thaliana ) leaf development. Single mutations in MIR319A and MIR319B genes moderately inhibited the formation of leaf serrations, whereas double mutations increased the extent of this inhibition and resulted in the formation of smooth leaves. Mutations in MIR319 and gain-of-function mutations in the TCP4 gene conferred resistance against miR319 and impaired the cotyledon boundary and leaf serration formation. These mutations functionally associated with CUP-SHAPED COTYLEDON genes, which regulate the cotyledon boundary and leaf serration formation. In contrast, loss-of-function mutations in miR319-targeted and nontargeted TCP genes cooperatively induced the formation of serrated leaves in addition to changes in the levels of their downstream gene transcript. Taken together, these findings demonstrate that the MIR319 and TCP gene families underlie robust and multilayer control of leaf development. This study also provides a framework toward future researches on redundant miRNAs and transcription factors in Arabidopsis and crop plants. © 2017 American Society of Plant Biologists. All Rights Reserved.

  12. A Phylogenomic Investigation of CYCLOIDEA-Like TCP Genes in the Leguminosae1

    PubMed Central

    Citerne, Hélène L.; Luo, Da; Pennington, R. Toby; Coen, Enrico; Cronk, Quentin C.B.

    2003-01-01

    Numerous TCP genes (transcription factors with a TCP domain) occur in legumes. Genes of this class in Arabidopsis (TCP1) and snapdragon (Antirrhinum majus; CYCLOIDEA) have been shown to be asymmetrically expressed in developing floral primordia, and in snapdragon, they are required for floral zygomorphy (bilaterally symmetrical flowers). These genes are therefore particularly interesting in Leguminosae, a family that is thought to have evolved zygomorphy independently from other zygomorphic angiosperm lineages. Using a phylogenomic approach, we show that homologs of TCP1/CYCLOIDEA occur in legumes and may be divided into two main classes (LEGCYC group I and II), apparently the result of an early duplication, and each class is characterized by a typical amino acid signature in the TCP domain. Furthermore, group I genes in legumes may be divided into two subclasses (LEGCYC IA and IB), apparently the result of a duplication near the base of the papilionoid legumes or below. Most papilionoid legumes investigated have all three genes present (LEGCYC IA, IB, and II), inviting further work to investigate possible functional difference between the three types. However, within these three major gene groups, the precise relationships of the paralogs between species are difficult to determine probably because of a complex history of duplication and loss with lineage sorting or heterotachy (within-site rate variation) due to functional differentiation. The results illustrate both the potential and the difficulties of orthology determination in variable gene families, on which the phylogenomic approach to formulating hypotheses of function depends. PMID:12644657

  13. TCP throughput adaptation in WiMax networks using replicator dynamics.

    PubMed

    Anastasopoulos, Markos P; Petraki, Dionysia K; Kannan, Rajgopal; Vasilakos, Athanasios V

    2010-06-01

    The high-frequency segment (10-66 GHz) of the IEEE 802.16 standard seems promising for the implementation of wireless backhaul networks carrying large volumes of Internet traffic. In contrast to wireline backbone networks, where channel errors seldom occur, the TCP protocol in IEEE 802.16 Worldwide Interoperability for Microwave Access networks is conditioned exclusively by wireless channel impairments rather than by congestion. This renders a cross-layer design approach between the transport and physical layers more appropriate during fading periods. In this paper, an adaptive coding and modulation (ACM) scheme for TCP throughput maximization is presented. In the current approach, Internet traffic is modulated and coded employing an adaptive scheme that is mathematically equivalent to the replicator dynamics model. The stability of the proposed ACM scheme is proven, and the dependence of the speed of convergence on various physical-layer parameters is investigated. It is also shown that convergence to the strategy that maximizes TCP throughput may be further accelerated by increasing the amount of information from the physical layer.

  14. The TCP4 transcription factor of Arabidopsis blocks cell division in yeast at G1→S transition.

    PubMed

    Aggarwal, Pooja; Padmanabhan, Bhavna; Bhat, Abhay; Sarvepalli, Kavitha; Sadhale, Parag P; Nath, Utpal

    2011-07-01

    The TCP transcription factors control important aspects of plant development. Members of class I TCP proteins promote cell cycle by regulating genes directly involved in cell proliferation. In contrast, members of class II TCP proteins repress cell division. While it has been postulated that class II proteins induce differentiation signal, their exact role on cell cycle has not been studied. Here, we report that TCP4, a class II TCP protein from Arabidopsis that repress cell proliferation in developing leaves, inhibits cell division by blocking G1→S transition in budding yeast. Cells expressing TCP4 protein with increased transcriptional activity fail to progress beyond G1 phase. By analyzing global transcriptional status of these cells, we show that expression of a number of cell cycle genes is altered. The possible mechanism of G1→S arrest is discussed. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. The TCP4 transcription factor regulates trichome cell differentiation by directly activating GLABROUS INFLORESCENCE STEMS in Arabidopsis thaliana.

    PubMed

    Vadde, Batthula Vijaya Lakshmi; Challa, Krishna Reddy; Nath, Utpal

    2018-01-01

    Trichomes are the first cell type to be differentiated during the morphogenesis of leaf epidermis and serve as an ideal model to study cellular differentiation. Many genes involved in the patterning and differentiation of trichome cells have been studied over the past decades, and the majority of these genes encode transcription factors that specifically regulate epidermal cell development. However, the upstream regulators of these genes that link early leaf morphogenesis with cell type differentiation are less studied. The TCP proteins are the plant-specific transcription factors involved in regulating diverse aspects of plant development including lateral organ morphogenesis by modulating cell proliferation and differentiation. Here, we show that the miR319-regulated class II TCP proteins, notably TCP4, suppress trichome branching in Arabidopsis leaves and inflorescence stem by direct transcriptional activation of GLABROUS INFLORESCENCE STEMS (GIS), a known negative regulator of trichome branching. The trichome branch number is increased in plants with reduced TCP activity and decreased in the gain-of-function lines of TCP4. Biochemical analyses show that TCP4 binds to the upstream regulatory region of GIS and activates its expression. Detailed genetic analyses show that GIS and TCP4 work in same pathway and GIS function is required for TCP4-mediated regulation of trichome differentiation. Taken together, these results identify a role for the class II TCP genes in trichome differentiation, thus providing a connection between organ morphogenesis and cellular differentiation. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  16. In vitro neurotoxic hazard characterization of different tricresyl phosphate (TCP) isomers and mixtures.

    PubMed

    Duarte, Daniel J; Rutten, Joost M M; van den Berg, Martin; Westerink, Remco H S

    2017-03-01

    Exposure to tricresyl phosphates (TCPs), via for example contaminated cabin air, has been associated with health effects including the so-called aerotoxic syndrome. While TCP neurotoxicity is mainly attributed to ortho-isomers like tri-ortho-cresyl phosphate (ToCP), recent exposure and risk assessments indicate that ToCP levels in cabin air are very low. However, the neurotoxic potential of non-ortho TCP isomers and TCP mixtures is largely unknown. We therefore measured effects of exposure (up to 48h) to different TCP isomers, mixtures and the metabolite of ToCP (CBDP: cresyl saligenin phosphate) on cell viability and mitochondrial activity, spontaneous neuronal electrical activity, and neurite outgrowth in primary rat cortical neurons. The results demonstrate that exposure to TCPs (24-48h, up to 10μM) increases mitochondrial activity, without affecting cell viability. Effects of acute TCP exposure (30min) on neuronal electrical activity are limited. However, electrical activity is markedly decreased for the majority of TCPs (10μM) following 48h exposure. Additional preliminary data indicate that exposure to TCPs (48h, 10μM) did not affect the number of neurites per cell or average neurite length, except for TmCP and the analytical TCP mixture (Sigma) that induced a reduction of average neurite length. The combined neurotoxicity data demonstrate that the different TCPs, including ToCP, are roughly equipotent and a clear structure-activity relation is not apparent for the studied endpoints. The no-observed-effect-concentrations (1μM) are well above current exposure levels indicating limited neurotoxic health risk, although exposures may have been higher in the past. Moreover, prolonged and/or repeated exposure to TCPs may exacerbate the observed neurotoxic effects, which argues for additional research. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Assessment of tricalcium phosphate/collagen (TCP/collagene)nanocomposite scaffold compared with hydroxyapatite (HA) on healing of segmental femur bone defect in rabbits.

    PubMed

    Mohseni, Mahmoud; Jahandideh, Alireza; Abedi, Gholamreza; Akbarzadeh, Abolfazl; Hesaraki, Saeed

    2018-03-01

    Bone regeneration is an important objective in clinical practice and has been used for different applications. The aim of this study was to evaluate the effectiveness of nanocomposite tricalcium phosphate (TCP)/collagen scaffolds combined with hydroxyapatite scaffold for bone healing in surgery of femoral defects in rabbits. In this study, 45 mature male New Zealand white rabbits between 6 and 8 months old and weighting between 3 and 3.5 kg were examined. Rabbits were divided into three groups. Surgical procedures were performed after intramuscular injection of Ketamine 10% (ketamine hydrochloride, 50 mg/kg) and Rompun 5% (xylazine, 5 mg/kg). Then an approximately 6 mm diameter-5 mm cylinder bone defect was created in the femur of one of the hind limbs. After inducing the surgical wound, all rabbits were coloured and randomly divided into three experimental groups of 15 animals each. Group 1 received pure medical nanocomposite TCP/collagen granules, group 2 received hydroxyapatite, and third group was a control group which received no treatment. Histopathological evaluation was performed on days 15, 30, and 45 after surgery. On days 15, 30, and 45 after surgery, the quantity and the velocity of stages of bone formation at the healing site in nanocomposite TCP/collagen group were better than HA and control groups and the quantity of newly formed lamellar bone at the healing site in nanocomposite TCP/collagen group were better than onward compared with HA and control groups. In conclusion, it seems that TCP/collagen nanocomposite has a significant role in the reconstruction of bone defects and can be used as scaffold in bone fractures.

  18. Soft Tissue Augmentation with Autologous Platelet Gel and β-TCP: A Histologic and Histometric Study in Mice.

    PubMed

    Scarano, Antonio; Ceccarelli, Maurizio; Marchetti, Massimiliano; Piattelli, Adriano; Mortellaro, Carmen

    2016-01-01

    Background. Facial aging is a dynamic process involving both soft tissue and bony structures. Skin atrophy, with loss of tone, elasticity, and distribution of facial fat, coupled with gravity and muscle activity, leads to wrinkling and folds. Purpose. The aim of the study was to evaluate microporous tricalcium phosphate (β-TCP) and autologous platelet gel (APG) mix in mice for oral and maxillofacial soft tissue augmentation. The hypothesis was that β-TCP added with APG was able to increase the biostimulating effect on fibroblasts and quicken resorption. Materials and Methods. Ten female, 6-8-week-old black-haired mice were selected. β-TCP/APG gel was injected into one cheek; the other was used as control. The animals were sacrificed at 8 weeks and histologically evaluated. Results. The new fibroblast was intensively stained with acid fuchsin and presented in contact with β-TCP. At higher magnification, actively secreting fibroblasts were observed at the periphery of β-TCP with a well differentiated fibroblast cell line and blood vessels. Acid fuchsin stained cutaneous structures in pink: no epidermal/dermal alterations or pathological inflammatory infiltrates were detected. The margins of β-TCP granules were clear and not diffused near tissues. Conclusion. APG with β-TCP preserves skin morphology, without immune response, with an excellent tolerability and is a promising scaffold for cells and biomaterial for soft tissue augmentation.

  19. Soft Tissue Augmentation with Autologous Platelet Gel and β-TCP: A Histologic and Histometric Study in Mice

    PubMed Central

    Ceccarelli, Maurizio; Marchetti, Massimiliano; Piattelli, Adriano; Mortellaro, Carmen

    2016-01-01

    Background. Facial aging is a dynamic process involving both soft tissue and bony structures. Skin atrophy, with loss of tone, elasticity, and distribution of facial fat, coupled with gravity and muscle activity, leads to wrinkling and folds. Purpose. The aim of the study was to evaluate microporous tricalcium phosphate (β-TCP) and autologous platelet gel (APG) mix in mice for oral and maxillofacial soft tissue augmentation. The hypothesis was that β-TCP added with APG was able to increase the biostimulating effect on fibroblasts and quicken resorption. Materials and Methods. Ten female, 6–8-week-old black-haired mice were selected. β-TCP/APG gel was injected into one cheek; the other was used as control. The animals were sacrificed at 8 weeks and histologically evaluated. Results. The new fibroblast was intensively stained with acid fuchsin and presented in contact with β-TCP. At higher magnification, actively secreting fibroblasts were observed at the periphery of β-TCP with a well differentiated fibroblast cell line and blood vessels. Acid fuchsin stained cutaneous structures in pink: no epidermal/dermal alterations or pathological inflammatory infiltrates were detected. The margins of β-TCP granules were clear and not diffused near tissues. Conclusion. APG with β-TCP preserves skin morphology, without immune response, with an excellent tolerability and is a promising scaffold for cells and biomaterial for soft tissue augmentation. PMID:27478828

  20. Bone Regeneration in Critical Bone Defects Using Three-Dimensionally Printed β-Tricalcium Phosphate/Hydroxyapatite Scaffolds Is Enhanced by Coating Scaffolds with Either Dipyridamole or BMP-2

    PubMed Central

    Ishack, Stephanie; Mediero, Aranzazu; Wilder, Tuere; Ricci, John L.; Cronstein, Bruce N.

    2017-01-01

    Bone defects resulting from trauma or infection need timely and effective treatments to restore damaged bone. Using specialized three-dimensional (3-D) printing technology we have created custom 3-D scaffolds of hydroxyapatite (HA)/Beta-Tri-Calcium Phosphate (β-TCP) to promote bone repair. To further enhance bone regeneration we have coated the scaffolds with dipyridamole, an agent that increases local adenosine levels by blocking cellular uptake of adenosine. 15% HA:85% β-TCP scaffolds were designed using Robocad software, fabricated using a 3-D Robocasting system, and sintered at 1100°C for 4h. Scaffolds were coated with BMP-2 (200ng/ml), Dypiridamole 100µM or saline and implanted in C57B6 and adenosine A2A receptor knockout (A2AKO) mice with 3mm cranial critical bone defects for 2-8 weeks. Dipyridamole release from scaffold was assayed spectrophotometrically. MicroCT and histological analysis were performed. micro-computed tomography (microCT) showed significant bone formation and remodeling in HA/β-TCP- dipyridamole and HA/β-TCP -BMP-2 scaffolds when compared to scaffolds immersed in vehicle at 2, 4 and 8 weeks (n=5 per group; p≤ 0.05, p≤ 0.05 and p≤ 0.01, respectively). Histological analysis showed increased bone formation and a trend toward increased remodeling in HA/β-TCP- dipyridamole and HA/β-TCP-BMP-2 scaffolds. coating scaffolds with dipyridamole did not enhance bone regeneration in A2AKO mice. In conclusion, scaffolds printed with HA/β-TCP promote bone regeneration in critical bone defects and coating these scaffolds with agents that stimulate A2A receptors and growth factors can further enhance bone regeneration. These coated scaffolds may be very useful for treating critical bone defects due to trauma, infection or other causes. PMID:26513656

  1. Inhibition of osteolysis after local administration of osthole in a TCP particles-induced osteolysis model.

    PubMed

    Lv, Shumin; Zhang, Yun; Yan, Ming; Mao, Hongjiao; Pan, Cailing; Gan, Mingxiao; Fan, Jiawen; Wang, Guoxia

    2016-07-01

    Wear debris-induced osteolysis and aseptic loosening are the most frequent late complications of total joint arthroplasty leading to revision of the prosthesis. However, no effective measures for the prevention and treatment of particles-induced osteolysis currently exist. Here, we investigated the efficacy of local administration of osthole on tricalcium phosphate (TCP) particles-induced osteolysis in a murine calvarial model. TCP particles were implanted over the calvaria of ICR mice, and established TCP particles-induced osteolysis model. On days one, four, seven, ten and thirteen post-surgery, osthole (10 mg/kg) or phosphate buffer saline (PBS) were subcutaneously injected into the calvaria of TCP particles-implanted or sham-operated mice. Two weeks later, blood, the periosteum and the calvaria were collected and processed for bone turnover markers, pro-inflammatory cytokine, histomorphometric and molecular analysis. Osthole (10 mg/kg) markedly prevented TCP particles-induced osteoclastogenesis and bone resorption in a mouse calvarial model. Osthole also inhibited the decrease of serum osteocalcin level and calvarial alkaline phosphatase (ALP) activity, and prevented the increase in the activity of tartrate resistant acid phosphatase (TRAP) and cathepsin K in the mouse calvaria. Furthermore, osthole obviously reduced the release of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) into the periosteum. Western blotting demonstrated TCP particles caused a remarkable endoplasmic reticulum (ER) stress response in the mouse calvaria, which was obviously blocked by osthole treatment. These results suggest that local administration of osthole inhibits TCP particles-induced osteolysis in the mouse calvarial in vivo, which may be mediated by inhibition of the ER stress signaling pathway, and it will be developed as a new drug in the prevention and treatment of destructive diseases caused by prosthetic wear particles.

  2. Combining Phylogenetic and Syntenic Analyses for Understanding the Evolution of TCP ECE Genes in Eudicots

    PubMed Central

    Citerne, Hélène L.; Le Guilloux, Martine; Sannier, Julie; Nadot, Sophie; Damerval, Catherine

    2013-01-01

    TCP ECE genes encode transcription factors which have received much attention for their repeated recruitment in the control of floral symmetry in core eudicots, and more recently in monocots. Major duplications of TCP ECE genes have been described in core eudicots, but the evolutionary history of this gene family is unknown in basal eudicots. Reconstructing the phylogeny of ECE genes in basal eudicots will help set a framework for understanding the functional evolution of these genes. TCP ECE genes were sequenced in all major lineages of basal eudicots and Gunnera which belongs to the sister clade to all other core eudicots. We show that in these lineages they have a complex evolutionary history with repeated duplications. We estimate the timing of the two major duplications already identified in the core eudicots within a timeframe before the divergence of Gunnera and after the divergence of Proteales. We also use a synteny-based approach to examine the extent to which the expansion of TCP ECE genes in diverse eudicot lineages may be due to genome-wide duplications. The three major core-eudicot specific clades share a number of collinear genes, and their common evolutionary history may have originated at the γ event. Genomic comparisons in Arabidopsis thaliana and Solanum lycopersicum highlight their separate polyploid origin, with syntenic fragments with and without TCP ECE genes showing differential gene loss and genomic rearrangements. Comparison between recently available genomes from two basal eudicots Aquilegia coerulea and Nelumbo nucifera suggests that the two TCP ECE paralogs in these species are also derived from large-scale duplications. TCP ECE loci from basal eudicots share many features with the three main core eudicot loci, and allow us to infer the makeup of the ancestral eudicot locus. PMID:24019982

  3. Leaf expansion in Arabidopsis is controlled by a TCP-NGA regulatory module likely conserved in distantly related species.

    PubMed

    Ballester, Patricia; Navarrete-Gómez, Marisa; Carbonero, Pilar; Oñate-Sánchez, Luis; Ferrándiz, Cristina

    2015-09-01

    The NGATHA (NGA) clade of transcription factors (TFs) forms a small subfamily of four members in Arabidopsis thaliana. NGA genes act redundantly to direct the development of apical tissues in the gynoecium, where they have been shown to be essential for style and stigma specification. In addition, NGA genes have a more general role in controlling lateral organ growth. The four NGA genes in Arabidopsis are expressed in very similar domains, although little is known about the nature of their putative regulators. Here, we have identified a conserved region within the four NGA promoters that we have used as a bait to screen a yeast library, aiming to identify such NGA regulators. Three members of the TCP family of TFs, named after the founding factors TEOSINTE BRANCHED 1, CYCLOIDEA and PROLIFERATING CELL FACTOR 1 AND 2), were recovered from this screening, of which two [TCP2 and TCP3, members of the CINCINNATA (CIN) family of TCP genes (CIN-TCP) subclade] were shown to activate the NGA3 promoter in planta. We provide evidence that support that CIN-TCP genes are true regulators of NGA gene expression, and that part of the CIN-TCP role in leaf development is mediated by NGA upregulation. Moreover, we have found that this TCP-NGA regulatory interaction is likely conserved in angiosperms, including important crop species, for which the regulation of leaf development is a target for biotechnological improvement. © 2015 Scandinavian Plant Physiology Society.

  4. Mixing TCP and Satellites: A View from Above

    NASA Technical Reports Server (NTRS)

    Travis, Eric

    1998-01-01

    Various issues associated with "Mixing TCP and Satellites: A View from Above" are presented in viewgraph form. Specific topics include: 1) Why are open protocol standards important?; and 2) Protocols are like galoshes: One size does not fit all.

  5. Redox modulation of plant developmental regulators from the class I TCP transcription factor family.

    PubMed

    Viola, Ivana L; Güttlein, Leandro N; Gonzalez, Daniel H

    2013-07-01

    TEOSINTE BRANCHED1-CYCLOIDEA-PROLIFERATING CELL FACTOR1 (TCP) transcription factors participate in plant developmental processes associated with cell proliferation and growth. Most members of class I, one of the two classes that compose the family, have a conserved cysteine at position 20 (Cys-20) of the TCP DNA-binding and dimerization domain. We show that Arabidopsis (Arabidopsis thaliana) class I proteins with Cys-20 are sensitive to redox conditions, since their DNA-binding activity is inhibited after incubation with the oxidants diamide, oxidized glutathione, or hydrogen peroxide or with nitric oxide-producing agents. Inhibition can be reversed by treatment with the reductants dithiothreitol or reduced glutathione or by incubation with the thioredoxin/thioredoxin reductase system. Mutation of Cys-20 in the class I protein TCP15 abolished its redox sensitivity. Under oxidizing conditions, covalently linked dimers were formed, suggesting that inactivation is associated with the formation of intermolecular disulfide bonds. Inhibition of class I TCP protein activity was also observed in vivo, in yeast (Saccharomyces cerevisiae) cells expressing TCP proteins and in plants after treatment with redox agents. This inhibition was correlated with modifications in the expression of the downstream CUC1 gene in plants. Modeling studies indicated that Cys-20 is located at the dimer interface near the DNA-binding surface. This places this residue in the correct orientation for intermolecular disulfide bond formation and explains the sensitivity of DNA binding to the oxidation of Cys-20. The redox properties of Cys-20 and the observed effects of cellular redox agents both in vitro and in vivo suggest that class I TCP protein action is under redox control in plants.

  6. Maxillary Sinus Lift with Beta-Tricalcium Phosphate (β-TCP) in Edentulous Patients: A Nanotomographic and Raman Study.

    PubMed

    Pascaretti-Grizon, Florence; Guillaume, Bernard; Terranova, Lisa; Arbez, Baptiste; Libouban, Hélène; Chappard, Daniel

    2017-09-01

    Sinus lift elevation restores bone mass at the maxilla in edentulate patients before the placement of dental implants. It consists of opening the lateral side of the sinus and grafting beta-tricalcium phosphate granules (β-TCP) under the olfactory membrane. Bone biopsies were obtained in five patients after 60 weeks. They were embedded undecalcified in poly(methyl methacrylate) (pMMA); blocks were analyzed by nanocomputed tomography (nanoCT); specific areas were studied by Raman microspectroscopy. Remnants of β-TCP were osseointegrated and covered with mineralized bone; osteoid tissue was also filling the inner porosity. Macrophages having engulfed numerous β-TCP grains were observed in marrow spaces. β-TCP was identified by nanoCT as osseointegrated particles and as granules in the cytoplasm of macrophages. Raman microspectroscopy permitted to compare the spectra of β-TCP and bone in different areas. The ratio of the ~820 cm -1 band of pMMA (-CH 2 groups) on the ν1 phosphate band at 960 cm -1 reflected tissue hydration because water was substituted by MMA during histological processing. In bone, the ratio of the ~960 cm -1 phosphate to the amide 1 band and the ratio ν2 phosphate band by the 1240-1250 amide III band reflect the mineralization degree. Specific bands of β-TCP were found in osseointegrated β-TCP granules and in the grains phagocytized by the macrophages. The hydration degree was maximal for β-TCP phagocytized by macrophages. Raman microspectroscopy associated with nanoCT is a powerful tool in the analysis of the biomaterial degradation and osseointegration.

  7. Potential implications of the bystander effect on TCP and EUD when considering target volume dose heterogeneity.

    PubMed

    Balderson, Michael J; Kirkby, Charles

    2015-01-01

    In light of in vitro evidence suggesting that radiation-induced bystander effects may enhance non-local cell killing, there is potential for impact on radiotherapy treatment planning paradigms such as the goal of delivering a uniform dose throughout the clinical target volume (CTV). This work applies a bystander effect model to calculate equivalent uniform dose (EUD) and tumor control probability (TCP) for external beam prostate treatment and compares the results with a more common model where local response is dictated exclusively by local absorbed dose. The broad assumptions applied in the bystander effect model are intended to place an upper limit on the extent of the results in a clinical context. EUD and TCP of a prostate cancer target volume under conditions of increasing dose heterogeneity were calculated using two models: One incorporating bystander effects derived from previously published in vitro bystander data ( McMahon et al. 2012 , 2013a); and one using a common linear-quadratic (LQ) response that relies exclusively on local absorbed dose. Dose through the CTV was modelled as a normal distribution, where the degree of heterogeneity was then dictated by changing the standard deviation (SD). Also, a representative clinical dose distribution was examined as cold (low dose) sub-volumes were systematically introduced. The bystander model suggests a moderate degree of dose heterogeneity throughout a target volume will yield as good or better outcome compared to a uniform dose in terms of EUD and TCP. For a typical intermediate risk prostate prescription of 78 Gy over 39 fractions maxima in EUD and TCP as a function of increasing SD occurred at SD ∼ 5 Gy. The plots only dropped below the uniform dose values for SD ∼ 10 Gy, almost 13% of the prescribed dose. Small, but potentially significant differences in the outcome metrics between the models were identified in the clinically-derived dose distribution as cold sub-volumes were introduced. In terms of

  8. Serum Immunoproteomics Combined With Pathological Reassessment of Surgical Specimens Identifies TCP-1ζ Autoantibody as a Potential Biomarker in Thyroid Neoplasia.

    PubMed

    Belousov, Pavel V; Bogolyubova, Apollinariya V; Kim, Yan S; Abrosimov, Alexander Y; Kopylov, Arthur T; Tvardovskiy, Andrey A; Lanshchakov, Kirill V; Sazykin, Alexei Y; Dvinskikh, Nina Y; Bobrovskaya, Yana I; Selivanova, Lilia S; Shilov, Evgeniy S; Schwartz, Anton M; Shebzukhov, Yuriy V; Severskaia, Natalya V; Vanushko, Vladimir E; Moshkovskii, Sergei A; Nedospasov, Sergei A; Kuprash, Dmitry V

    2015-09-01

    Current methods of preoperative diagnostics frequently fail to discriminate between benign and malignant thyroid neoplasms. In encapsulated follicular-patterned tumors (EnFPT), this discrimination is challenging even using histopathological analysis. Autoantibody response against tumor-associated antigens is a well-documented phenomenon with prominent diagnostic potential; however, autoantigenicity of thyroid tumors remains poorly explored. Objectives were exploration of tumor-associated antigen repertoire of thyroid tumors and identification of candidate autoantibody biomarkers capable of discrimination between benign and malignant thyroid neoplasms. Proteins isolated from FTC-133 cells were subjected to two-dimensional Western blotting using pooled serum samples of patients originally diagnosed with either papillary thyroid carcinoma (PTC) or EnFPT represented by apparently benign follicular thyroid adenomas, as well as healthy individuals. Immunoreactive proteins were identified using liquid chromatography-tandem mass-spectrometry. Pathological reassessment of EnFPT was performed applying nonconservative criteria for capsular invasion and significance of focal PTC nuclear changes (PTC-NCs). Recombinant T-complex protein 1 subunitζ (TCP-1ζ) was used to examine an expanded serum sample set of patients with various thyroid neoplasms (n = 89) for TCP-1ζ autoantibodies. All patients were included in tertiary referral centers. A protein demonstrating a distinct pattern of EnFPT-specific seroreactivity was identified as TCP-1ζ protein. A subsequent search for clinicopathological correlates of TCP-1ζ seroreactivity revealed nonclassical capsular invasion or focal PTC-NC in all TCP-1ζ antibody-positive cases. Further studies in an expanded sample set confirmed the specificity of TCP-1ζ autoantibodies to malignant EnFPT. We identified TCP-1ζ autoantibodies as a potential biomarker for presurgical discrimination between benign and malignant encapsulated follicular

  9. Genome-Wide Identification and Analysis of TCP Transcription Factors Involved in the Formation of Leafy Head in Chinese Cabbage.

    PubMed

    Liu, Yan; Guan, Xiaoyu; Liu, Shengnan; Yang, Meng; Ren, Junhui; Guo, Meng; Huang, Zhihui; Zhang, Yaowei

    2018-03-14

    Chinese cabbage ( Brassica rapa L. ssp . pekinensis ) is a widely cultivated and economically important vegetable crop with typical leaf curvature. The TCP (Teosinte branched1, Cycloidea, Proliferating cell factor) family proteins are plant-specific transcription factors (TFs) and play important roles in many plant biological processes, especially in the regulation of leaf curvature. In this study, 39 genes encoding TCP TFs are detected on the whole genome of B. rapa. Based on the phylogenetic analysis of TCPs between Arabidopsis thaliana and Brassica rapa , TCP genes of Chinese cabbage are named from BrTCP1a to BrTCP24b . Moreover, the chromosomal location; phylogenetic relationships among B. rapa , A. thaliana , and rice; gene structures and protein conserved sequence alignment; and conserved domains are analyzed. The expression profiles of BrTCPs are analyzed in different tissues. To understand the role of Chinese cabbage TCP members in regulating the curvature of leaves, the expression patterns of all BrTCP genes are detected at three development stages essential for leafy head formation. Our results provide information on the classification and details of BrTCPs and allow us to better understand the function of TCPs involved in leaf curvature of Chinese cabbage.

  10. High time for a roll call: gene duplication and phylogenetic relationships of TCP-like genes in monocots

    PubMed Central

    Mondragón-Palomino, Mariana; Trontin, Charlotte

    2011-01-01

    Background and Aims The TCP family is an ancient group of plant developmental transcription factors that regulate cell division in vegetative and reproductive structures and are essential in the establishment of flower zygomorphy. In-depth research on eudicot TCPs has documented their evolutionary and developmental role. This has not happened to the same extent in monocots, although zygomorphy has been critical for the diversification of Orchidaceae and Poaceae, the largest families of this group. Investigating the evolution and function of TCP-like genes in a wider group of monocots requires a detailed phylogenetic analysis of all available sequence information and a system that facilitates comparing genetic and functional information. Methods The phylogenetic relationships of TCP-like genes in monocots were investigated by analysing sequences from the genomes of Zea mays, Brachypodium distachyon, Oryza sativa and Sorghum bicolor, as well as EST data from several other monocot species. Key Results All available monocot TCP-like sequences are associated in 20 major groups with an average identity ≥64 % and most correspond to well-supported clades of the phylogeny. Their sequence motifs and relationships of orthology were documented and it was found that 67 % of the TCP-like genes of Sorghum, Oryza, Zea and Brachypodium are in microsyntenic regions. This analysis suggests that two rounds of whole genome duplication drove the expansion of TCP-like genes in these species. Conclusions A system of classification is proposed where putative or recognized monocot TCP-like genes are assigned to a specific clade of PCF-, CIN- or CYC/tb1-like genes. Specific biases in sequence data of this family that must be tackled when studying its molecular evolution and phylogeny are documented. Finally, the significant retention of duplicated TCP genes from Zea mays is considered in the context of balanced gene drive. PMID:21444336

  11. Evaluation of 3D printed PCL/PLGA/β-TCP versus collagen membranes for guided bone regeneration in a beagle implant model.

    PubMed

    Won, J-Y; Park, C-Y; Bae, J-H; Ahn, G; Kim, C; Lim, D-H; Cho, D-W; Yun, W-S; Shim, J-H; Huh, J-B

    2016-10-07

    Here, we compared 3D-printed polycaprolactone/poly(lactic-co-glycolic acid)/β-tricalcium phosphate (PCL/PLGA/β-TCP) membranes with the widely used collagen membranes for guided bone regeneration (GBR) in beagle implant models. For mechanical property comparison in dry and wet conditions and cytocompatibility determination, we analyzed the rate and pattern of cell proliferation of seeded fibroblasts and preosteoblasts using the cell counting kit-8 assay and scanning electron microscopy. Osteogenic differentiation was verified using alizarin red S staining. At 8 weeks following implantation in vivo using beagle dogs, computed tomography and histological analyses were performed after sacrifice. Cell proliferation rates in vitro indicated that early cell attachment was higher in collagen than in PCL/PLGA/β-TCP membranes; however, the difference subsided by day 7. Similar outcomes were found for osteogenic differentiation, with approximately 2.5 times greater staining in collagen than PCL/PLGA/β-TCP, but without significant difference by day 14. In vivo, bone regeneration in the defect area, represented by new bone formation and bone-to-implant contact, paralleled those associated with collagen membranes. However, tensile testing revealed that whereas the PCL/PLGA/β-TCP membrane mechanical properties were conserved in both wet and dry states, the tensile property of collagen was reduced by 99% under wet conditions. Our results demonstrate in vitro and in vivo that PCL/PLGA/β-TCP membranes have similar levels of biocompatibility and bone regeneration as collagen membranes. In particular, considering that GBR is always applied to a wet environment (e.g. blood, saliva), we demonstrated that PCL/PLGA/β-TCP membranes maintained their form more reliably than collagen membranes in a wet setting, confirming their appropriateness as a GBR membrane.

  12. TCP performance in ATM networks: ABR parameter tuning and ABR/UBR comparisons

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chien Fang; Lin, A.

    1996-02-27

    This paper explores two issues on TOP performance over ATM networks: ABR parameter tuning and performance comparison of binary mode ABR with enhanced UBR services. Of the fifteen parameters defined for ABR, two parameters dominate binary mode ABR performance: Rate Increase Factor (RIF) and Rate Decrease Factor (RDF). Using simulations, we study the effects of these two parameters on TOP over ABR performance. We compare TOP performance with different ABR parameter settings in terms of through-puts and fairness. The effects of different buffer sizes and LAN/WAN distances are also examined. We then compare TOP performance with the best ABR parametermore » setting with corresponding UBR service enhanced with Early Packet Discard and also with a fair buffer allocation scheme. The results show that TOP performance over binary mode ABR is very sensitive to parameter value settings, and that a poor choice of parameters can result in ABR performance worse than that of the much less expensive UBR-EPD scheme.« less

  13. Low modulus and bioactive Ti/α-TCP/Ti-mesh composite prepared by spark plasma sintering.

    PubMed

    Guo, Yu; Tan, Yanni; Liu, Yong; Liu, Shifeng; Zhou, Rui; Tang, Hanchun

    2017-11-01

    A titanium mesh scaffold composite filled with Ti/α-TCP particles was prepared by spark plasma sintering (SPS). The microstructures and interfacial reactions of the composites were investigated by scanning electron microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and X-ray diffraction (XRD) analyses. The compressive strength and elastic modulus were also measured. In vitro bioactivity and biocompatibility was evaluated by using simulated body fluid and cells culture, respectively. After high temperature sintering, Ti oxides, Ti x P y and CaTiO 3 were formed. The formation of Ti oxides and Ti x P y were resulted from the diffusion of O and P elements from α-TCP to Ti. CaTiO 3 was the reaction product of Ti and α-TCP. The composite of 70Ti/α-TCP incorporated with Ti mesh showed a high compressive strength of 589MPa and a low compressive modulus of 30GPa. The bioactivity test showed the formation of a thick apatite layer on the composite and well-spread cells attachment. A good combination of mechanical properties and bioactivity indicated a high potential application of Ti/α-TCP/Ti-mesh composite for orthopedic implants. Copyright © 2017. Published by Elsevier B.V.

  14. Degradation kinetics of chlorpyrifos and 3,5,6-trichloro-2-pyridinol (TCP) by fungal communities.

    PubMed

    Maya, K; Upadhyay, S N; Singh, R S; Dubey, Suresh K

    2012-12-01

    Fungal isolates obtained from soil were used for degrading chlorpyrifos (CP) and TCP. The percentage degradation ranged from 69.4 to 89.8 for CP and 62.2 to 92.6 for TCP after one week. The values of K(s) and V(max) were different for different isolates. The K(s) ranged from 66.66 to 169.5mg/L and V(max) from 6.56 to 40.4 mg/L/d for CP and from 53.19 to 163.9 mg/L and 3.41 to 40.40 mg/L/d, respectively, for TCP. Fungal community showed high affinity for both CP and TCP. The genetic relatedness of isolate F1 to Aspergillus sp., F2 and F3 to Penicillium sp., F4 to Eurotium sp. and F5 to Emericella sp. were confirmed. The degradation potential was in the order: F1>F2=F3>F4>F5. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Internet and Intranet Use with a PC: Effects of Adapter Cards, Windows Versions and TCP/IP Software on Networking Performance.

    ERIC Educational Resources Information Center

    Nieuwenhuysen, Paul

    1997-01-01

    Explores data transfer speeds obtained with various combinations of hardware and software components through a study of access to the Internet from a notebook computer connected to a local area network based on Ethernet and TCP/IP (transmission control protocol/Internet protocol) network protocols. Upgrading is recommended for higher transfer…

  16. Effect of Mg(2+) doping on beta-alpha phase transition in tricalcium phosphate (TCP) bioceramics.

    PubMed

    Frasnelli, Matteo; Sglavo, Vincenzo M

    2016-03-01

    The beta to alpha transition in tricalcium phosphate (TCP) bioceramics containing different amount of magnesium was studied in the present work. Mg-doped TCP powder was obtained by solid-state reaction starting from pure calcium carbonate, ammonium phosphate dibasic and magnesium oxide powders. The β to α transformation temperature was identified by dilatometric and thermo-differential analyses. Small pellets produced by uniaxial pressing samples were employed to study the influence of Mg(2+) on the transition kinetic, after sintering at 1550°C and subsequent slow or fast cooling down to room temperature. The evolution of β- and α-TCP crystalline phases during each thermal treatment was determined by X-ray powder diffraction analysis combined with Rietveld method-based software An annealing treatment, suitable to reconvert metastable α phase to the more clinically suitable β phase, was also investigated. It is shown that the presence of magnesium within the TCP lattice strongly influences the kinetic of the β⇆α phase transition, promoting the spontaneous α→β reconversion even upon fast cooling, or slowing down the β→α transition during heating. Similarly, it allows the α→β transformation in TCP sintered components by optimized annealing treatment at 850°C. This work concerns the effect of Mg(2+) doping on the β→α phase reconstructive transition in tricalcium phosphate (TCP), one of the most important bio-resorbable materials for bone tissue regeneration. The transition occurs upon the sintering process and is has been shown to be strongly irreversible upon cooling, leading to technological issues such as poor mechanical properties and excessive solubility due to the presence of metastable α-phase. This paper points out the kinetic contribution of Mg(2+) on the spontaneous α→β reconversion also upon fast cooling (i.e. quenching). Moreover, an annealing treatment has been shown to be beneficial to remove the retained α-phase in

  17. U.S. Coast Guard Telecommunications Plan (TCP) - Development Document

    DOT National Transportation Integrated Search

    1997-04-28

    The Coast Guard Telecommunications Plan (TCP) describes the near to mid-term telecommunications goals and objectives for Command, Control, and Communications (C3) support. It is intended to document internal telecommunications planning and to provide...

  18. Achieving Fair Throughput among TCP Flows in Multi-Hop Wireless Mesh Networks

    NASA Astrophysics Data System (ADS)

    Hou, Ting-Chao; Hsu, Chih-Wei

    Previous research shows that the IEEE 802.11 DCF channel contention mechanism is not capable of providing throughput fairness among nodes in different locations of the wireless mesh network. The node nearest the gateway will always strive for the chance to transmit data, causing fewer transmission opportunities for the nodes farther from the gateway, resulting in starvation. Prior studies modify the DCF mechanism to address the fairness problem. This paper focuses on the fairness study when TCP flows are carried over wireless mesh networks. By not modifying lower layer protocols, the current work identifies TCP parameters that impact throughput fairness and proposes adjusting those parameters to reduce frame collisions and improve throughput fairness. With the aid of mathematical formulation and ns2 simulations, this study finds that frame transmission from each node can be effectively controlled by properly controlling the delayed ACK timer and using a suitable advertised window. The proposed method reduces frame collisions and greatly improves TCP throughput fairness.

  19. Genome-Wide Identification and Analysis of TCP Transcription Factors Involved in the Formation of Leafy Head in Chinese Cabbage

    PubMed Central

    Liu, Yan; Guan, Xiaoyu; Liu, Shengnan; Yang, Meng; Ren, Junhui; Guo, Meng; Huang, Zhihui

    2018-01-01

    Chinese cabbage (Brassica rapa L. ssp. pekinensis) is a widely cultivated and economically important vegetable crop with typical leaf curvature. The TCP (Teosinte branched1, Cycloidea, Proliferating cell factor) family proteins are plant-specific transcription factors (TFs) and play important roles in many plant biological processes, especially in the regulation of leaf curvature. In this study, 39 genes encoding TCP TFs are detected on the whole genome of B. rapa. Based on the phylogenetic analysis of TCPs between Arabidopsis thaliana and Brassica rapa, TCP genes of Chinese cabbage are named from BrTCP1a to BrTCP24b. Moreover, the chromosomal location; phylogenetic relationships among B. rapa, A. thaliana, and rice; gene structures and protein conserved sequence alignment; and conserved domains are analyzed. The expression profiles of BrTCPs are analyzed in different tissues. To understand the role of Chinese cabbage TCP members in regulating the curvature of leaves, the expression patterns of all BrTCP genes are detected at three development stages essential for leafy head formation. Our results provide information on the classification and details of BrTCPs and allow us to better understand the function of TCPs involved in leaf curvature of Chinese cabbage. PMID:29538304

  20. Technical Fact Sheet – 1,2,3-Trichloropropane (TCP)

    EPA Pesticide Factsheets

    This fact sheet, developed by the U.S. Environmental Protection Agency (EPA) Federal Facilities Restoration and Reuse Office (FFRRO), provides a brief summary of the contaminant 1,2,3-trichloropropane (TCP), including physical and chemical properties

  1. Technical Fact Sheet – 1,2,3-Trichloropropane (TCP)

    EPA Pesticide Factsheets

    This fact sheet, developed by the U.S. Environmental Protection Agency (EPA) Federal Facilities Restoration and Reuse Office (FFRRO), provides a brief summary of the contaminant 1,2,3-trichloropropane (TCP), including physical and chemical properties;

  2. Brucella TIR-like protein TcpB/Btp1 specifically targets the host adaptor protein MAL/TIRAP to promote infection.

    PubMed

    Li, Wenna; Ke, Yuehua; Wang, Yufei; Yang, Mingjuan; Gao, Junguang; Zhan, Shaoxia; Xinying, Du; Huang, Liuyu; Li, Wenfeng; Chen, Zeliang; Li, Juan

    2016-08-26

    Brucella spp. are known to avoid host immune recognition and weaken the immune response to infection. Brucella like accomplish this by employing two clever strategies, called the stealth strategy and hijacking strategy. The TIR domain-containing protein (TcpB/Btp1) of Brucella melitensis is thought to be involved in inhibiting host NF-κB activation by binding to adaptors downstream of Toll-like receptors. However, of the five TIR domain-containing adaptors conserved in mammals, whether MyD88 or MAL, even other three adaptors, are specifically targeted by TcpB has not been identified. Here, we confirmed the effect of TcpB on B.melitensis virulence in mice and found that TcpB selectively targets MAL. By using siRNA against MAL, we found that TcpB from B.melitensis is involved in intracellular survival and that MAL affects intracellular replication of B.melitensis. Our results confirm that TcpB specifically targets MAL/TIRAP to disrupt downstream signaling pathways and promote intra-host survival of Brucella spp. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. In vivo interference with AtTCP20 function induces severe plant growth alterations and deregulates the expression of many genes important for development.

    PubMed

    Hervé, Christine; Dabos, Patrick; Bardet, Claude; Jauneau, Alain; Auriac, Marie Christine; Ramboer, Agnès; Lacout, Fabrice; Tremousaygue, Dominique

    2009-03-01

    AtTCP20 is a transcription factor belonging to the Arabidopsis (Arabidopsis thaliana) TCP-P subfamily, characterized by its capacity to bind to site II motifs (TGGGCY). Our aim was to understand the role of AtTCP20 in plant development. The expression pattern of a translational fusion of Prom(TCP20):CDS20GUSGFP suggested a function for AtTCP20 in several plant organs and stages of development. The role of AtTCP20 was challenged in planta by inducing expression of AtTCP20 proteins fused with either a transcriptional activator domain (VP16) or a repressor domain (EAR). Expression of both modified proteins led to severe developmental phenotypes. In-depth analysis suggested that AtTCP20 may participate in the regulation of cell expansion, cell division, and cell differentiation. Gene expression profiling in roots and hypocotyls revealed that 252 genes were down-regulated in both organs after induction of the AtTCP20EAR repressor gene. Site II motifs (TGGGCY) were underrepresented in their promoters. Conversely, GG(A/T)CCC sequences related to binding sites identified for TCP proteins in rice (Oryza sativa) were overrepresented, and a TCP20 fusion protein was shown to bind to these sequences in vitro. Gene ontology indicated that many targeted genes were involved in cell wall biogenesis and modification during expansion and also encoded numerous transcription factors controlling plant development. Our results are consistent with the previous proposal that AtTCP20 is involved in cell division and growth coordination. Moreover, they further suggest that AtTCP20 also contributes to cell expansion control and indicate a different involvement of this protein in plant morphogenesis depending on the organ and the developmental stage.

  4. Effect of biomimetic zinc-containing tricalcium phosphate (Zn-TCP) on the growth and osteogenic differentiation of mesenchymal stem cells.

    PubMed

    Chou, Joshua; Hao, Jia; Hatoyama, Hirokazu; Ben-Nissan, Besim; Milthorpe, Bruce; Otsuka, Makoto

    2015-07-01

    Several studies have shown the effectiveness of zinc-tricalcium phosphate (Zn-TCP) for bone tissue engineering. In this study, marine calcareous foraminifera possessing uniform pore size distribution were hydrothermally converted to Zn-TCP. The ability of a scaffold to combine effectively with mesenchymal stem cells (MSCs) is a key tissue-engineering aim. In order to demonstrate the osteogenic ability of MSCs with Zn-TCP, the scaffolds were cultured in an osteogenic induction medium to elicit an osteoblastic response. The physicochemical properties of Zn-TCP were characterized by XRD, FT-IR and ICP-MS. MSCs were aspirated from rat femurs and cultured for 3 days before indirectly placing four samples into each respective well. After culture for 7, 10 and 14 days, osteoblastic differentiation was evaluated using alizarin red S stain, measurement of alkaline phosphatase (ALP) levels, cell numbers and cell viability. XRD and FT-IR patterns both showed the replacement of CO(3)(2-) with PO(4)(3-). Chemical analysis showed zinc incorporation of 5 mol%. Significant increases in cell numbers were observed at 10 and 14 days in the Zn-TCP group, while maintaining high levels of cell viability (> 90%). ALP activity in the Zn-TCP group was statistically higher at 10 days. Alizarin red S staining also showed significantly higher levels of calcium mineralization in Zn-TCP compared with the control groups. This study showed that MSCs in the presence of biomimetically derived Zn-TCP can accelerate their differentiation to osteoblasts and could potentially be useful as a scaffold for bone tissue engineering. Copyright © 2014 John Wiley & Sons, Ltd.

  5. Roles of miR319 and TCP Transcription Factors in Leaf Development1[OPEN

    PubMed Central

    2017-01-01

    Sophisticated regulation of gene expression, including microRNAs (miRNAs) and their target genes, is required for leaf differentiation, growth, and senescence. The impact of miR319 and its target TEOSINTE BRANCHED1, CYCLOIDEA, and PROLIFERATING CELL NUCLEAR ANTIGEN BINDING FACTOR (TCP) genes on leaf development has been extensively investigated, but the redundancies of these gene families often interfere with the evaluation of their function and regulation in the developmental context. Here, we present the genetic evidence of the involvement of the MIR319 and TCP gene families in Arabidopsis (Arabidopsis thaliana) leaf development. Single mutations in MIR319A and MIR319B genes moderately inhibited the formation of leaf serrations, whereas double mutations increased the extent of this inhibition and resulted in the formation of smooth leaves. Mutations in MIR319 and gain-of-function mutations in the TCP4 gene conferred resistance against miR319 and impaired the cotyledon boundary and leaf serration formation. These mutations functionally associated with CUP-SHAPED COTYLEDON genes, which regulate the cotyledon boundary and leaf serration formation. In contrast, loss-of-function mutations in miR319-targeted and nontargeted TCP genes cooperatively induced the formation of serrated leaves in addition to changes in the levels of their downstream gene transcript. Taken together, these findings demonstrate that the MIR319 and TCP gene families underlie robust and multilayer control of leaf development. This study also provides a framework toward future researches on redundant miRNAs and transcription factors in Arabidopsis and crop plants. PMID:28842549

  6. Optimally designed collagen/polycaprolactone biocomposites supplemented with controlled release of HA/TCP/rhBMP-2 and HA/TCP/PRP for hard tissue regeneration.

    PubMed

    Kim, WonJin; Jang, Chul Ho; Kim, GeunHyung

    2017-09-01

    Collagen has been widely used as a very promising material to regenerate various tissues. It is a chief component of the extracellular matrix, and encourages various biological effects conducive to tissue regeneration. However, poor mechanical stability, low processability, and high level of water absorption can lead to impaired control of growth factor release and have impeded the use of collagen as a functional biomedical scaffold. Here, to overcome the shortcomings of collagen scaffolds, we have additively manufactured collagen/polycaprolactone (PCL) biocomposites supplemented with a bioceramic (hydroxyapatite (HA)/β-tricalcium-phosphate (TCP)) and two growth factors (recombinant human bone morphogenetic protein-2 [rhBMP-2] and platelet-rich plasma [PRP]). Various weight fractions of PCL in the collagen/PCL composites were manipulated to select optimal growth factor release and highly active cellular responses. After the optimal concentration of PCL in the collagen/PCL scaffold was determined, biocomposites supplemented with bioceramic/growth-factors were fabricated. Continuously released growth factors were assumed to increase the in vitro cellular activities of the osteoblast-like cells (MG63) cultured on the biocomposites. In vitro cellular responses, including osteogenic activities, were examined, and results showed that compared to the HA/TCP/rhBMP-2 supplemented scaffold the HA/TCP/PRP biocomposites provide significantly high cellular activities (cell proliferation: >1.3-fold) and mineralization (calcium deposition: >1.4-fold, osteocalcin: >2.6-fold) sufficient for regenerating bone tissue. Copyright © 2017. Published by Elsevier B.V.

  7. A System Implementation for Cooperation between UHF RFID Reader and TCP/IP Device

    NASA Astrophysics Data System (ADS)

    Lee, Sang Hoon; Jin, Ik Soo

    This paper presents a system implementation for cooperation between UHF RFID reader and TCP/IP device that can be used as a home gateway. The system consists of an UHF RFID tag, an UHF RFID reader, a RF end-device, a RF coordinator and a TCP/IP I/F. The UHF RFID reader is compatible with EPC Class-0/Gen1, Class-1/Gen1, 2 and ISO18000-6B, operating at the 915MHz. In particular, UHF RFID reader can be combined with a RF end device/coordinator for ZigBee(IEEE 802.15.4) interface which is low power wireless standard. The TCP/IP device is communicated with RFID reader via wired type. On the other hand, it is connected with ZigBee end-device via wireless type. The experimental results show that the developed system can provide the right networking.

  8. Biocompatibility evaluation of HDPE-UHMWPE reinforced β-TCP nanocomposites using highly purified human osteoblast cells.

    PubMed

    Shokrgozar, M A; Farokhi, M; Rajaei, F; Bagheri, M H A; Azari, Sh; Ghasemi, I; Mottaghitalab, F; Azadmanesh, K; Radfar, J

    2010-12-15

    Biocompatibility of β-TCP/HDPE-UHMWPE nanocomposite as a new bone substitute material was evaluated by using highly purified human osteoblast cells. Human osteoblast cells were isolated from bone tissue and characterized by immunofluorescence Staining before and after purification using magnetic bead system. Moreover, proliferation, alkaline phosphatase production, cell attachment, calcium deposition, gene expression, and morphology of osteoblast cells on β-TCP/HDPE-UHMWPE nanocomposites were evaluated. The results have shown that the human osteoblast cells were successfully purified and were suitable for subsequent cell culturing process. The high proliferation rate of osteoblast cells on β-TCP/HDPE-UHMWPE nanocomposite confirmed the great biocompatibility of the scaffold. Expression of bone-specific genes was taken place after the cells were incubated in composite extract solutions. Furthermore, osteoblast cells were able to mineralize the matrix next to composite samples. Scanning electron microscopy demonstrated that cells had normal morphology on the scaffold. Thus, these results indicated that the nanosized β-TCP/HDPE-UHMWPE blend composites could be potential scaffold, which is used in bone tissue engineering. Copyright © 2010 Wiley Periodicals, Inc.

  9. Spectroscopic Confirmation of TCP J07134590-2112330 as a Galactic Classical Nova in Canis Major

    NASA Astrophysics Data System (ADS)

    Strader, Jay; Chomiuk, Laura; Bahramian, Arash; Swihart, Sam

    2018-03-01

    TCP J07134590-2112330 was discovered by Yuji Nakamura on 2018 March 24.5 UT as a 12 mag optical transient. We obtained spectroscopic observations of TCP J07134590-2112330 with the Goodman spectrograph on the 4-m SOAR telescope on 2018 Mar 25.1 UT, with a low-resolution spectrum (R 1200) covering 3850-7850 A. The spectrum indicates that TCP J07134590-2112330 is a young classical nova, with strong hydrogen Balmer emission lines and additional strong lines of [O I] and Fe II. The Balmer lines show P Cygni profiles; the FWHM of the H alpha emission component is 1250 km/s, and the absorption trough extends to -2000 km/s.

  10. Bone regeneration in critical bone defects using three-dimensionally printed β-tricalcium phosphate/hydroxyapatite scaffolds is enhanced by coating scaffolds with either dipyridamole or BMP-2.

    PubMed

    Ishack, Stephanie; Mediero, Aranzazu; Wilder, Tuere; Ricci, John L; Cronstein, Bruce N

    2017-02-01

    Bone defects resulting from trauma or infection need timely and effective treatments to restore damaged bone. Using specialized three-dimensional (3D) printing technology we have created custom 3D scaffolds of hydroxyapatite (HA)/beta-tri-calcium phosphate (β-TCP) to promote bone repair. To further enhance bone regeneration we have coated the scaffolds with dipyridamole, an agent that increases local adenosine levels by blocking cellular uptake of adenosine. Nearly 15% HA:85% β-TCP scaffolds were designed using Robocad software, fabricated using a 3D Robocasting system, and sintered at 1100°C for 4 h. Scaffolds were coated with BMP-2 (200 ng mL -1 ), dypiridamole 100 µM or saline and implanted in C57B6 and adenosine A2A receptor knockout (A2AKO) mice with 3 mm cranial critical bone defects for 2-8 weeks. Dipyridamole release from scaffold was assayed spectrophotometrically. MicroCT and histological analysis were performed. Micro-computed tomography (microCT) showed significant bone formation and remodeling in HA/β-TCP-dipyridamole and HA/β-TCP-BMP-2 scaffolds when compared to scaffolds immersed in vehicle at 2, 4, and 8 weeks (n = 5 per group; p ≤ 0.05, p ≤ 0.05, and p ≤ 0.01, respectively). Histological analysis showed increased bone formation and a trend toward increased remodeling in HA/β-TCP- dipyridamole and HA/β-TCP-BMP-2 scaffolds. Coating scaffolds with dipyridamole did not enhance bone regeneration in A2AKO mice. In conclusion, scaffolds printed with HA/β-TCP promote bone regeneration in critical bone defects and coating these scaffolds with agents that stimulate A2A receptors and growth factors can further enhance bone regeneration. These coated scaffolds may be very useful for treating critical bone defects due to trauma, infection or other causes. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 366-375, 2017. © 2015 Wiley Periodicals, Inc.

  11. Effect of Water-Glass Coating on HA and HA-TCP Samples for MSCs Adhesion, Proliferation, and Differentiation.

    PubMed

    Bajpai, Indu; Kim, Duk Yeon; Kyong-Jin, Jung; Song, In-Hwan; Kim, Sukyoung

    2016-01-01

    Ca-P and silicon based materials have become very popular as bone tissue engineering materials. In this study, water-glass (also known as sodium silicate glass) was coated on sintered hydroxyapatite (HA) and HA-TCP (TCP stands for tricalcium phosphate) samples and subsequently heat-treated at 600°C for 2 hrs. X-rays diffraction showed the presence of β- and α-TCP phases along with HA in the HA-TCP samples. Samples without coating, with water-glass coating, and heat-treated after water-glass coating were used to observe the adhesion and proliferation response of bone marrow derived-mesenchymal stem cells (MSCs). Cell culture was carried out for 4 hrs, 1 day, and 7 days. Interestingly, all samples showed similar response for cell adhesion and proliferation up to 7-day culture but fibronectin, E-cadherin, and osteogenic differentiation related genes (osteocalcin and osteopontin) were significantly induced in heat-treated water-glass coated HA-TCP samples. A water-glass coating on Ca-P samples was not found to influence the cell proliferation response significantly but activated some extracellular matrix genes and induced osteogenic differentiation in the MSCs.

  12. Ohio Medical Office Management. Technical Competency Profile (TCP).

    ERIC Educational Resources Information Center

    Ray, Gayl M.; Wilson, Nick; Mangini, Rick

    This document provides a framework for a broad-based secondary and postsecondary curriculum to prepare students for employment in medical office management. The first part of the technical competency profile (TCP) contains the following items: an explanation of the purpose and scope of Ohio's TCPs; college tech prep program standards; an overview…

  13. Bone Morphogenetic Protein-7 Enhances Degradation of Osteoinductive Bioceramic Implants in an Ectopic Model

    PubMed Central

    Klünter, Tim; Schulz, Peter; Deisinger, Ulrike; Diez, Claudius; Waiss, Waltraud; Kirschneck, Christian; Reichert, Torsten E.; Detsch, Rainer

    2017-01-01

    Background: The aim of the present study was to evaluate the degradation pattern of highly porous bioceramics as well as the bone formation in presence of bone morphogenetic protein 7 (BMP-7) in an ectopic site. Methods: Novel calcium phosphate ceramic cylinders sintered at 1,300°C with a total porosity of 92–94 vol%, 45 pores per inch, and sized 15 mm (Ø) × 5 mm were grafted on the musculus latissimus dorsi bilaterally in 10 Göttingen minipigs: group I (n = 5): hydroxyapatite (HA) versus biphasic calcium phosphate (BCP), a mixture of HA and tricalcium phosphate (TCP) in a ratio of 60/40 wt%; group II (n = 5): TCP versus BCP. A test side was supplied in situ with 250 μg BMP-7. Fluorochrome bone labeling and computed tomography were performed in vivo. Specimens were evaluated 14 weeks after surgery by environmental scanning electron microscopy, fluorescence microscopy, tartrate-resistant acid phosphatase, and pentachrome staining. Results: Bone formation was enhanced in the presence of BMP-7 in all ceramics (P = 0.001). Small spots of newly formed bone were observed in all implants in the absence of BMP-7. Degradation of HA and BCP was enhanced in the presence of BMP-7 (P = 0.001). In those ceramics, osteoclasts were observed. TCP ceramics were almost completely degraded independently of the effect of BMP-7 after 14 weeks (P = 0.76), osteoclasts were not observed. Conclusions: BMP-7 enhanced bone formation and degradation of HA and BCP ceramics via osteoclast resorption. TCP degraded via dissolution. All ceramics were osteoinductive. Novel degradable HA and BCP ceramics in the presence of BMP-7 are promising bone substitutes in the growing individual. PMID:28740783

  14. Misato Controls Mitotic Microtubule Generation by Stabilizing the TCP-1 Tubulin Chaperone Complex [corrected].

    PubMed

    Palumbo, Valeria; Pellacani, Claudia; Heesom, Kate J; Rogala, Kacper B; Deane, Charlotte M; Mottier-Pavie, Violaine; Gatti, Maurizio; Bonaccorsi, Silvia; Wakefield, James G

    2015-06-29

    Mitotic spindles are primarily composed of microtubules (MTs), generated by polymerization of α- and β-Tubulin hetero-dimers. Tubulins undergo a series of protein folding and post-translational modifications in order to fulfill their functions. Defects in Tubulin polymerization dramatically affect spindle formation and disrupt chromosome segregation. We recently described a role for the product of the conserved misato (mst) gene in regulating mitotic MT generation in flies, but the molecular function of Mst remains unknown. Here, we use affinity purification mass spectrometry (AP-MS) to identify interacting partners of Mst in the Drosophila embryo. We demonstrate that Mst associates stoichiometrically with the hetero-octameric Tubulin Chaperone Protein-1 (TCP-1) complex, with the hetero-hexameric Tubulin Prefoldin complex, and with proteins having conserved roles in generating MT-competent Tubulin. We show that RNAi-mediated in vivo depletion of any TCP-1 subunit phenocopies the effects of mutations in mst or the Prefoldin-encoding gene merry-go-round (mgr), leading to monopolar and disorganized mitotic spindles containing few MTs. Crucially, we demonstrate that Mst, but not Mgr, is required for TCP-1 complex stability and that both the efficiency of Tubulin polymerization and Tubulin stability are drastically compromised in mst mutants. Moreover, our structural bioinformatic analyses indicate that Mst resembles the three-dimensional structure of Tubulin monomers and might therefore occupy the TCP-1 complex central cavity. Collectively, our results suggest that Mst acts as a co-factor of the TCP-1 complex, playing an essential role in the Tubulin-folding processes required for proper assembly of spindle MTs. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Variation of mechanical behavior of β-TCP/collagen two phase composite scaffold with mesenchymal stem cell in vitro.

    PubMed

    Arahira, Takaaki; Todo, Mitsugu

    2016-08-01

    The primary aim of this study is to characterize the variational behavior of the compressive mechanical property of bioceramic-based scaffolds using stem cells during the cell culture period. β-Tricalcium phosphate (TCP)/collagen two phase composites and β-TCP scaffolds were fabricated using the polyurethane template technique and a subsequent freeze-drying method. Rat bone-marrow mesenchymal stem cells (rMSCs) were then cultured in these scaffolds for up to 28 days. Compression tests of the scaffolds with rMSCs were periodically conducted. Biological properties, such as the cell number, alkaline phosphatase (ALP) activity, and gene expressions of osteogenesis, were evaluated. The microstructural change due to cell growth and the formation of extracellular matrices was examined using a field-emission scanning electron microscope. The compressive property was then correlated with the biological properties and microstructures to understand the mechanism of the variational behavior of the macroscopic mechanical property. The porous collagen structure in the β-TCP scaffold effectively improved the structural stability of the composite scaffold, whereas the β-TCP scaffold exhibited structural instability with the collapse of the porous structure when immersed in a culture medium. The β-TCP/collagen composite scaffold exhibited higher ALP activity and more active generation of osteoblastic markers than the β-TCP scaffold. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. TCP Transcription Factors at the Interface between Environmental Challenges and the Plant's Growth Responses.

    PubMed

    Danisman, Selahattin

    2016-01-01

    Plants are sessile and as such their reactions to environmental challenges differ from those of mobile organisms. Many adaptions involve growth responses and hence, growth regulation is one of the most crucial biological processes for plant survival and fitness. The plant-specific TEOSINTE BRANCHED 1, CYCLOIDEA, PCF1 (TCP) transcription factor family is involved in plant development from cradle to grave, i.e., from seed germination throughout vegetative development until the formation of flowers and fruits. TCP transcription factors have an evolutionary conserved role as regulators in a variety of plant species, including orchids, tomatoes, peas, poplar, cotton, rice and the model plant Arabidopsis. Early TCP research focused on the regulatory functions of TCPs in the development of diverse organs via the cell cycle. Later research uncovered that TCP transcription factors are not static developmental regulators but crucial growth regulators that translate diverse endogenous and environmental signals into growth responses best fitted to ensure plant fitness and health. I will recapitulate the research on TCPs in this review focusing on two topics: the discovery of TCPs and the elucidation of their evolutionarily conserved roles across the plant kingdom, and the variety of signals, both endogenous (circadian clock, plant hormones) and environmental (pathogens, light, nutrients), TCPs respond to in the course of their developmental roles.

  17. Exosomes/tricalcium phosphate combination scaffolds can enhance bone regeneration by activating the PI3K/Akt signaling pathway.

    PubMed

    Zhang, Jieyuan; Liu, Xiaolin; Li, Haiyan; Chen, Chunyuan; Hu, Bin; Niu, Xin; Li, Qing; Zhao, Bizeng; Xie, Zongping; Wang, Yang

    2016-09-20

    Recently, accumulating evidence has shown that exosomes, the naturally secreted nanocarriers of cells, can exert therapeutic effects in various disease models in the absence of parent cells. However, application of exosomes in bone defect repair and regeneration has been rarely reported, and little is known regarding their underlying mechanisms. Exosomes derived from human-induced pluripotent stem cell-derived mesenchymal stem cells (hiPS-MSC-Exos) were combined with tricalcium phosphate (β-TCP) to repair critical-sized calvarial bone defects, and the efficacy was assessed by histological examination. We evaluated the in vitro effects of hiPSC-MSC-Exos on the proliferation, migration, and osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs) by cell-counting, scratch assays, and qRT-PCR, respectively. Gene expression profiling and bioinformatics analyses were also used to identify the underlying mechanisms in the repair. We found that the exosome/β-TCP combination scaffolds could enhance osteogenesis as compared to pure β-TCP scaffolds. In vitro assays showed that the exosomes could release from β-TCP and could be internalized by hBMSCs. In addition, the internalization of exosomes into hBMSCs could profoundly enhance the proliferation, migration, and osteogenic differentiation of hBMSCs. Furthermore, gene expression profiling and bioinformatics analyses demonstrated that exosome/β-TCP combination scaffolds significantly altered the expression of a network of genes involved in the PI3K/Akt signaling pathway. Functional studies further confirmed that the PI3K/Akt signaling pathway was the critical mediator during the exosome-induced osteogenic responses of hBMSCs. We propose that the exosomes can enhance the osteoinductivity of β-TCP through activating the PI3K/Akt signaling pathway of hBMSCs, which means that the exosome/β-TCP combination scaffolds possess better osteogenesis activity than pure β-TCP scaffolds. These

  18. TCP/IP Interface for the Satellite Orbit Analysis Program (SOAP)

    NASA Technical Reports Server (NTRS)

    Carnright, Robert; Stodden, David; Coggi, John

    2009-01-01

    The Transmission Control Protocol/ Internet protocol (TCP/IP) interface for the Satellite Orbit Analysis Program (SOAP) provides the means for the software to establish real-time interfaces with other software. Such interfaces can operate between two programs, either on the same computer or on different computers joined by a network. The SOAP TCP/IP module employs a client/server interface where SOAP is the server and other applications can be clients. Real-time interfaces between software offer a number of advantages over embedding all of the common functionality within a single program. One advantage is that they allow each program to divide the computation labor between processors or computers running the separate applications. Secondly, each program can be allowed to provide its own expertise domain with other programs able to use this expertise.

  19. MultiNet TCP/P/IP for VAX/VMS update

    NASA Technical Reports Server (NTRS)

    Vance, L. Stuart

    1991-01-01

    Outlines of device support; DECnet interoperability; installation; MultiNet services; domain name server; Telnet; FTP; SMTP; DECwindows over TCP/IP; BSD r services; remote printing; RPC services and NFS server; NFS client; netcontrol; diagnostics; programming support; and MultiNet features are presented in viewgraph format.

  20. The effectiveness of the controlled release of simvastatin from β-TCP macrosphere in the treatment of OVX mice.

    PubMed

    Chou, Joshua; Ito, Tomoko; Otsuka, Makoto; Ben-Nissan, Besim; Milthorpe, Bruce

    2016-03-01

    Simvastatin, a cholesterol treatment drug, has been shown to stimulate bone regeneration. As such, there has been an increase interest in the development of suitable materials and systems for the delivery of simvastatin. Without the appropriate dosage of simvastatin, the therapeutic effects on bone growth will be significantly reduced. Furthermore, similar to many pharmaceutical compounds, at high concentration simvastatin can cause various adverse side-effects. Given the associated side-effects with the usage of simvastatin, the development of suitable controlled drug release system is pertinent. Calcium phosphate in particularly beta-tricalcium phosphate (β-TCP) has been extensively studied and used as a carrier material for drug delivery system. In this study, Foraminifera exoskeletons were used as calcium carbonate precursor materials, which were hydrothermally converted to β-TCP as a carrier material for simvastatin. Natural marine exoskeletons posses interconnected and uniformly porous network capable of improving drug loading and release rate. To prolong the release of simvastatin, an apatite coating was made around the β-TCP sample and in vitro release studies in simulated body fluid (SBF) showed a significant decrease in release rate. Osteoporotic mice were used to examine the compare therapeutic effectiveness of β-TCP, β-TCP with simvastatin, apatite-coated β-TCP with simvastatin and direct injection of simvastatin near the right femur of the mice. Localized and systemic effect were compared with the femur of the non-implanted side (left) and showed that β-TCP with or without simvastatin was able to induce significant bone formation over 6 weeks. Mechanical analysis showed that apatite-coated β-TCP with simvastatin produced significantly stronger bones compared with other experimental groups. This study shows that natural exoskeletons with the appropriate structure can be successfully used as a drug delivery system for simvastatin and can its

  1. Immunizing Adult Female Mice with a TcpA-A2-CTB Chimera Provides a High Level of Protection for Their Pups in the Infant Mouse Model of Cholera

    PubMed Central

    Price, Gregory A.; Holmes, Randall K.

    2014-01-01

    Vibrio cholerae expresses two primary virulence factors, cholera toxin (CT) and the toxin-coregulated pilus (TCP). CT causes profuse watery diarrhea, and TCP (composed of repeating copies of the major pilin TcpA) is required for intestinal colonization by V. cholerae. Antibodies to CT or TcpA can protect against cholera in animal models. We developed a TcpA holotoxin-like chimera (TcpA-A2-CTB) to elicit both anti-TcpA and anti-CTB antibodies and evaluated its immunogenicity and protective efficacy in the infant mouse model of cholera. Adult female CD-1 mice were immunized intraperitoneally three times with the TcpA-A2-CTB chimera and compared with similar groups immunized with a TcpA+CTB mixture, TcpA alone, TcpA with Salmonella typhimurium flagellin subunit FliC as adjuvant, or CTB alone. Blood and fecal samples were analyzed for antigen-specific IgG or IgA, respectively, using quantitative ELISA. Immunized females were mated; their reared offspring were challenged orogastrically with 10 or 20 LD50 of V. cholerae El Tor N16961; and vaccine efficacy was assessed by survival of the challenged pups at 48 hrs. All pups from dams immunized with the TcpA-A2-CTB chimera or the TcpA+CTB mixture survived at both challenge doses. In contrast, no pups from dams immunized with TcpA+FliC or CTB alone survived at the 20 LD50 challenge dose, although the anti-TcpA or anti-CTB antibody level elicited by these immunizations was comparable to the corresponding antibody level achieved by immunization with TcpA-A2-CTB or TcpA+CTB. Taken together, these findings comprise strong preliminary evidence for synergistic action between anti-TcpA and anti-CTB antibodies in protecting mice against cholera. Weight loss analysis showed that only immunization of dams with TcpA-A2-CTB chimera or TcpA+CTB mixture protected their pups against excess weight loss from severe diarrhea. These data support the concept of including both TcpA and CTB as immunogens in development of an effective multivalent

  2. Predictive functional control for active queue management in congested TCP/IP networks.

    PubMed

    Bigdeli, N; Haeri, M

    2009-01-01

    Predictive functional control (PFC) as a new active queue management (AQM) method in dynamic TCP networks supporting explicit congestion notification (ECN) is proposed. The ability of the controller in handling system delay along with its simplicity and low computational load makes PFC a privileged AQM method in the high speed networks. Besides, considering the disturbance term (which represents model/process mismatches, external disturbances, and existing noise) in the control formulation adds some level of robustness into the PFC-AQM controller. This is an important and desired property in the control of dynamically-varying computer networks. In this paper, the controller is designed based on a small signal linearized fluid-flow model of the TCP/AQM networks. Then, closed-loop transfer function representation of the system is derived to analyze the robustness with respect to the network and controller parameters. The analytical as well as the packet-level ns-2 simulation results show the out-performance of the developed controller for both queue regulation and resource utilization. Fast response, low queue fluctuations (and consequently low delay jitter), high link utilization, good disturbance rejection, scalability, and low packet marking probability are other features of the developed method with respect to other well-known AQM methods such as RED, PI, and REM which are also simulated for comparison.

  3. Bioresorbable β-TCP-FeAg nanocomposites for load bearing bone implants: High pressure processing, properties and cell compatibility.

    PubMed

    Swain, S K; Gotman, I; Unger, R; Gutmanas, E Y

    2017-09-01

    In this paper, the processing and properties of iron-toughened bioresorbable β-tricalcium phosphate (β-TCP) nanocomposites are reported. β-TCP is chemically similar to bone mineral and thus a good candidate material for bioresorbable bone healing devices; however intrinsic brittleness and low bending strength make it unsuitable for use in load-bearing sites. Near fully dense β-TCP-matrix nanocomposites containing 30vol% Fe, with and without addition of silver, were produced employing high energy attrition milling of powders followed by high pressure consolidation/cold sintering at 2.5GPa. In order to increase pure iron's corrosion rate, 10 to 30vol% silver were added to the metal phase. The degradation behavior of the developed composite materials was studied by immersion in Ringer's and saline solutions for up to 1month. The mechanical properties, before and after immersion, were tested in compression and bending. All the compositions exhibited high mechanical strength, the strength in bending being several fold higher than that of polymer toughened β-TCP-30PLA nanocomposites prepared by the similar procedure of attrition milling and cold sintering, and of pure high-temperature sintered β-TCP. Partial substitution of iron with silver led to an increase in both strength and ductility. Furthermore, the galvanic action of silver particles dispersed in the iron phase significantly accelerated in vitro degradation of β-TCP-30(Fe-Ag) nanocomposites. After 1month immersion, the composites retained about 50% of their initial bending strength. In cell culture experiments, β-TCP-27Fe3Ag nanocomposites exhibited no signs of cytotoxicity towards human osteoblasts suggesting that they can be used as an implant material. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Genome-wide Identification of TCP Family Transcription Factors from Populus euphratica and Their Involvement in Leaf Shape Regulation

    PubMed Central

    Ma, Xiaodong; Ma, Jianchao; Fan, Di; Li, Chaofeng; Jiang, Yuanzhong; Luo, Keming

    2016-01-01

    Higher plants have been shown to experience a juvenile vegetative phase, an adult vegetative phase, and a reproductive phase during its postembryonic development and distinct lateral organ morphologies have been observed at the different development stages. Populus euphratica, commonly known as a desert poplar, has developed heteromorphic leaves during its development. The TCP family genes encode a group of plant-specific transcription factors involved in several aspects of plant development. In particular, TCPs have been shown to influence leaf size and shape in many herbaceous plants. However, whether these functions are conserved in woody plants remains unknown. In the present study, we carried out genome-wide identification of TCP genes in P. euphratica and P. trichocarpa, and 33 and 36 genes encoding putative TCP proteins were found, respectively. Phylogenetic analysis of the poplar TCPs together with Arabidopsis TCPs indicated a biased expansion of the TCP gene family via segmental duplications. In addition, our results have also shown a correlation between different expression patterns of several P. euphratica TCP genes and leaf shape variations, indicating their involvement in the regulation of leaf shape development. PMID:27605130

  5. Differential osteogenic activity of osteoprogenitor cells on HA and TCP/HA scaffold of tissue engineered bone.

    PubMed

    Ng, Angela M H; Tan, K K; Phang, M Y; Aziyati, O; Tan, G H; Isa, M R; Aminuddin, B S; Naseem, M; Fauziah, O; Ruszymah, B H I

    2008-05-01

    Biomaterial, an essential component of tissue engineering, serves as a scaffold for cell attachment, proliferation, and differentiation; provides the three dimensional (3D) structure and, in some applications, the mechanical strength required for the engineered tissue. Both synthetic and naturally occurring calcium phosphate based biomaterial have been used as bone fillers or bone extenders in orthopedic and reconstructive surgeries. This study aims to evaluate two popular calcium phosphate based biomaterial i.e., hydroxyapatite (HA) and tricalcium phosphate/hydroxyapatite (TCP/HA) granules as scaffold materials in bone tissue engineering. In our strategy for constructing tissue engineered bone, human osteoprogenitor cells derived from periosteum were incorporated with human plasma-derived fibrin and seeded onto HA or TCP/HA forming 3D tissue constructs and further maintained in osteogenic medium for 4 weeks to induce osteogenic differentiation. Constructs were subsequently implanted intramuscularly in nude mice for 8 weeks after which mice were euthanized and constructs harvested for evaluation. The differential cell response to the biomaterial (HA or TCP/HA) adopted as scaffold was illustrated by the histology of undecalcified constructs and evaluation using SEM and TEM. Both HA and TCP/HA constructs showed evidence of cell proliferation, calcium deposition, and collagen bundle formation albeit lesser in the former. Our findings demonstrated that TCP/HA is superior between the two in early bone formation and hence is the scaffold material of choice in bone tissue engineering. Copyright 2007 Wiley Periodicals, Inc.

  6. Hyper-activation of the TCP4 transcription factor in Arabidopsis thaliana accelerates multiple aspects of plant maturation.

    PubMed

    Sarvepalli, Kavitha; Nath, Utpal

    2011-08-01

    Plant organs are initiated as primordial outgrowths, and require controlled cell division and differentiation to achieve their final size and shape. Superimposed on this is another developmental program that orchestrates the switch from vegetative to reproductive to senescence stages in the life cycle. These require sequential function of heterochronic regulators. Little is known regarding the coordination between organ and organismal growth in plants. The TCP gene family encodes transcription factors that control diverse developmental traits, and a subgroup of class II TCP genes regulate leaf morphogenesis. Absence of these genes results in large, crinkly leaves due to excess division, mainly at margins. It has been suggested that these class II TCPs modulate the spatio-temporal control of differentiation in a growing leaf, rather than regulating cell proliferation per se. However, the link between class II TCP action and cell growth has not been established. As loss-of-function mutants of individual TCP genes in Arabidopsis are not very informative due to gene redundancy, we generated a transgenic line that expressed a hyper-activated form of TCP4 in its endogenous expression domain. This resulted in premature onset of maturation and decreased cell proliferation, leading to much smaller leaves, with cup-shaped lamina in extreme cases. Further, the transgenic line initiated leaves faster than wild-type and underwent precocious reproductive maturation due to a shortened adult vegetative phase. Early senescence and severe fertility defects were also observed. Thus, hyper-activation of TCP4 revealed its role in determining the timing of crucial developmental events, both at the organ and organism level. © 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd.

  7. Redox Modulation of Plant Developmental Regulators from the Class I TCP Transcription Factor Family1[W][OA

    PubMed Central

    Viola, Ivana L.; Güttlein, Leandro N.; Gonzalez, Daniel H.

    2013-01-01

    TEOSINTE BRANCHED1-CYCLOIDEA-PROLIFERATING CELL FACTOR1 (TCP) transcription factors participate in plant developmental processes associated with cell proliferation and growth. Most members of class I, one of the two classes that compose the family, have a conserved cysteine at position 20 (Cys-20) of the TCP DNA-binding and dimerization domain. We show that Arabidopsis (Arabidopsis thaliana) class I proteins with Cys-20 are sensitive to redox conditions, since their DNA-binding activity is inhibited after incubation with the oxidants diamide, oxidized glutathione, or hydrogen peroxide or with nitric oxide-producing agents. Inhibition can be reversed by treatment with the reductants dithiothreitol or reduced glutathione or by incubation with the thioredoxin/thioredoxin reductase system. Mutation of Cys-20 in the class I protein TCP15 abolished its redox sensitivity. Under oxidizing conditions, covalently linked dimers were formed, suggesting that inactivation is associated with the formation of intermolecular disulfide bonds. Inhibition of class I TCP protein activity was also observed in vivo, in yeast (Saccharomyces cerevisiae) cells expressing TCP proteins and in plants after treatment with redox agents. This inhibition was correlated with modifications in the expression of the downstream CUC1 gene in plants. Modeling studies indicated that Cys-20 is located at the dimer interface near the DNA-binding surface. This places this residue in the correct orientation for intermolecular disulfide bond formation and explains the sensitivity of DNA binding to the oxidation of Cys-20. The redox properties of Cys-20 and the observed effects of cellular redox agents both in vitro and in vivo suggest that class I TCP protein action is under redox control in plants. PMID:23686421

  8. The intrinsically disordered C-terminal region of Arabidopsis thaliana TCP8 transcription factor acts both as a transactivation and self-assembly domain.

    PubMed

    Valsecchi, Isabel; Guittard-Crilat, Emilie; Maldiney, Régis; Habricot, Yvette; Lignon, Sabrina; Lebrun, Régine; Miginiac, Emile; Ruelland, Eric; Jeannette, Emmanuelle; Lebreton, Sandrine

    2013-09-01

    TCPs are plant specific transcription factors with non-canonical basic helix-loop-helix domains. While Arabidopsis thaliana has 24 TCPs involved in cell proliferation and differentiation, their mode of action has not been fully elucidated. Using bioinformatic tools, we demonstrate that TCP transcription factors belong to the intrinsically disordered proteins (IDP) family and that disorder is higher in class I TCPs than in class II TCPs. In particular, using bioinformatic and biochemical approaches, we have characterized TCP8, a class I TCP. TCP8 exhibits three intrinsically disordered regions (IDR) made of more than 50 consecutive residues, in which phosphorylable Ser residues are mainly clustered. Phosphorylation of Ser-211 that belongs to the central IDR was confirmed by mass spectrometry. Yeast two-hybrid assays also showed that the C-terminal IDR corresponds to a transactivation domain. Moreover, biochemical experiments demonstrated that TCP8 tends to oligomerize in dimers, trimers and higher-order multimers. Bimolecular fluorescence complementation (BiFC) experiments carried out on a truncated form of TCP8 lacking the C-terminal IDR indicated that it is effectively required for the pronounced self-assembly of TCP8. These data were reinforced by the prediction of a coiled coil domain in this IDR. The C-terminal IDR acts thus as an oligomerization domain and also a transactivation domain. Moreover, many Molecular Recognition Features (MoRFs) were predicted, indicating that TCP8 could interact with several partners to fulfill a fine regulation of transcription in response to various stimuli.

  9. Ohio Marketing Management and Research. Technical Competency Profile (TCP).

    ERIC Educational Resources Information Center

    Ray, Gayl M.; Wilson, Nick; Mangini, Rick

    This document provides a framework for a broad-based secondary and postsecondary curriculum to prepare students for employment in marketing management and research (MMR). The first part of the technical competency profile (TCP) contains the following items: an explanation of the purpose and scope of Ohio's TCPs; college tech prep program…

  10. A robust fractional-order PID controller design based on active queue management for TCP network

    NASA Astrophysics Data System (ADS)

    Hamidian, Hamideh; Beheshti, Mohammad T. H.

    2018-01-01

    In this paper, a robust fractional-order controller is designed to control the congestion in transmission control protocol (TCP) networks with time-varying parameters. Fractional controllers can increase the stability and robustness. Regardless of advantages of fractional controllers, they are still not common in congestion control in TCP networks. The network parameters are time-varying, so the robust stability is important in congestion controller design. Therefore, we focused on the robust controller design. The fractional PID controller is developed based on active queue management (AQM). D-partition technique is used. The most important property of designed controller is the robustness to the time-varying parameters of the TCP network. The vertex quasi-polynomials of the closed-loop characteristic equation are obtained, and the stability boundaries are calculated for each vertex quasi-polynomial. The intersection of all stability regions is insensitive to network parameter variations, and results in robust stability of TCP/AQM system. NS-2 simulations show that the proposed algorithm provides a stable queue length. Moreover, simulations show smaller oscillations of the queue length and less packet drop probability for FPID compared to PI and PID controllers. We can conclude from NS-2 simulations that the average packet loss probability variations are negligible when the network parameters change.

  11. Repair of calvarial bone defects in mice using electrospun polystyrene scaffolds combined with β-TCP or gold nanoparticles.

    PubMed

    Terranova, Lisa; Dragusin, Diana Maria; Mallet, Romain; Vasile, Eugeniu; Stancu, Izabela-Cristina; Behets, Catherine; Chappard, Daniel

    2017-02-01

    Non-biodegradable porous polystyrene (PS) scaffolds, composed of microfibers, have been prepared by electrospinning for the reconstruction of large bone defects. PS microfibers were prepared by incorporating β-TCP grains inside the polymer or grafting gold nanoparticles surface functionalized with mercaptosuccinic acid. Cytocompatibility of the three types of scaffolds (PS, β-TCP-PS and Au-PS) was studied by seeding human mesenchymal stem cells. Biocompatibility was evaluated by implanting β-TCP-PS and Au-PS scaffolds into a critical size (4mm) calvarial defect in mice. Calvaria were taken 6, 9, and 12 weeks after implantation; newly formed bone and cellular response was analyzed by microcomputed tomography (microCT) and histology. β-TCP-PS scaffolds showed a significantly higher cell proliferation in vitro than on PS or Au-PS alone; clearly, the presence of β-TCP grains improved cytocompatibility. Biocompatibility study in the mouse calvaria model showed that β-TCP-PS scaffolds were significantly associated with more newly-formed bone than Au-PS. Bone developed by osteoconduction from the defect margins to the center. A dense fibrous connective tissue containing blood vessels was identified histologically in both types of scaffolds. There was no inflammatory foci nor giant cell in these areas. AuNPs aggregates were identified histologically in the fibrosis and also incorporated in the newly-formed bone matrix. Although the different types of PS microfibers appeared cytocompatible during the in vitro experiment, they appeared biotolerated in vivo since they induced a fibrotic reaction associated with newly formed bone. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. αTCP ceramic doped with dicalcium silicate for bone regeneration applications prepared by powder metallurgy method: in vitro and in vivo studies.

    PubMed

    Velasquez, Pablo; Luklinska, Zofia B; Meseguer-Olmo, Luis; Mate-Sanchez de Val, Jose E; Delgado-Ruiz, Rafael A; Calvo-Guirado, Jose L; Ramirez-Fernandez, Ma P; de Aza, Piedad N

    2013-07-01

    This study reports on the in vitro and in vivo behavior of α-tricalcium phosphate (αTCP) and also αTCP doped with either 1.5 or 3.0 wt % of dicalcium silicate (C2 S). The ceramics were successfully prepared by powder metallurgy method combined with homogenization and heat treatment procedures. All materials were composed of a single-phase, αTCP in the case of a pure material, or solid solution of C2 S in αTCP for the doped αTCP, which were stable at room temperature. The ceramics were tested for bioactivity in simulated body fluid, cell culture medium containing adult mesenchymal stem cells of human origin, and in animals. Analytical scanning electron microscopy combined with chemical elemental analysis was used and Fourier transform infrared and conventional histology methods. The in vivo behavior of the ceramics matched the in vitro results, independently of the C2 S content in αTCP. Carbonated hydroxyapatite (CHA) layer was formed on the surface and within the inner parts of the specimens in all cases. A fully mineralized new bone growing in direct contact with the implants was found under the in vivo conditions. The bioactivity and biocompatibility of the implants increased with the C2 S content in αTCP. The C2 S doped ceramics also favoured a phase transformation of αTCP into CHA, important for full implant integration during the natural bone healing processes. αTCP ceramic doped with 3.0 wt % C2 S showed the best bioactive in vitro and in vivo properties of all the compositions and hence could be of interest in specific applications for bone restorative purposes. Copyright © 2012 Wiley Periodicals, Inc.

  13. Achieving High Performance With TCP Over 40 GbE on NUMA Architectures for CMS Data Acquisition

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bawej, Tomasz; et al.

    2014-01-01

    TCP and the socket abstraction have barely changed over the last two decades, but at the network layer there has been a giant leap from a few megabits to 100 gigabits in bandwidth. At the same time, CPU architectures have evolved into the multicore era and applications are expected to make full use of all available resources. Applications in the data acquisition domain based on the standard socket library running in a Non-Uniform Memory Access (NUMA) architecture are unable to reach full efficiency and scalability without the software being adequately aware about the IRQ (Interrupt Request), CPU and memory affinities.more » During the first long shutdown of LHC, the CMS DAQ system is going to be upgraded for operation from 2015 onwards and a new software component has been designed and developed in the CMS online framework for transferring data with sockets. This software attempts to wrap the low-level socket library to ease higher-level programming with an API based on an asynchronous event driven model similar to the DAT uDAPL API. It is an event-based application with NUMA optimizations, that allows for a high throughput of data across a large distributed system. This paper describes the architecture, the technologies involved and the performance measurements of the software in the context of the CMS distributed event building.« less

  14. Structure, mechanical property and corrosion behaviors of (HA+β-TCP)/Mg-5Sn composite with interpenetrating networks.

    PubMed

    Wang, X; Li, J T; Xie, M Y; Qu, L J; Zhang, P; Li, X L

    2015-11-01

    In this paper, a novel (Hydroxyapatite+β-tricalcium phosphate)/Mg-5Sn ((HA+β-TCP)/Mg-5Sn) composite with interpenetrating networks was fabricated by infiltrating Mg-5Sn alloy into porous HA+β-TCP using suction casting technique. The structure, mechanical property and corrosion behaviors of the composite have been evaluated by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), mechanical testing, electrochemical and immersion test. It is shown that the molten Mg-5Sn alloy has infiltrated not only into the pores but also into the struts of the HA+β-TCP scaffold to forming a compact composite. The microstructure observation also shows that the Mg alloy contacts to the HA+β-TCP closely, and no reaction layer can be found between Mg-5Sn alloy and scaffold. The ultimate compressive strength of the composite is as high as 176MPa, which is about four fifths of the strength of the Mg-5Sn bulk alloy. The electrochemical and immersion tests indicate that the corrosion resistance of the composite is better than that of the Mg-5Sn bulk alloy. The corrosion products on the composite surface are mainly Mg(OH)2, Ca3(PO4)2 and HA. Appropriate mechanical and corrosion properties of the (HA+β-TCP)/Mg-5Sn composite indicate its possibility for new bone tissue implant materials. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. SU-D-16A-04: Accuracy of Treatment Plan TCP and NTCP Values as Determined Via Treatment Course Delivery Simulations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Siebers, J; Xu, H; Gordon, J

    2014-06-01

    Purpose: To to determine if tumor control probability (TCP) and normal tissue control probability (NTCP) values computed on the treatment planning image are representative of TCP/NTCP distributions resulting from probable positioning variations encountered during external-beam radiotherapy. Methods: We compare TCP/NTCP as typically computed on the planning PTV/OARs with distributions of those parameters computed for CTV/OARs via treatment delivery simulations which include the effect of patient organ deformations for a group of 19 prostate IMRT pseudocases. Planning objectives specified 78 Gy to PTV1=prostate CTV+5 mm margin, 66 Gy to PTV2=seminal vesicles+8 mm margin, and multiple bladder/rectum OAR objectives to achieve typicalmore » clinical OAR sparing. TCP were computed using the Poisson Model while NTCPs used the Lyman-Kutcher-Bruman model. For each patient, 1000 30-fraction virtual treatment courses were simulated with each fractional pseudo- time-oftreatment anatomy sampled from a principle component analysis patient deformation model. Dose for each virtual treatment-course was determined via deformable summation of dose from the individual fractions. CTVTCP/ OAR-NTCP values were computed for each treatment course, statistically analyzed, and compared with the planning PTV-TCP/OARNTCP values. Results: Mean TCP from the simulations differed by <1% from planned TCP for 18/19 patients; 1/19 differed by 1.7%. Mean bladder NTCP differed from the planned NTCP by >5% for 12/19 patients and >10% for 4/19 patients. Similarly, mean rectum NTCP differed by >5% for 12/19 patients, >10% for 4/19 patients. Both mean bladder and mean rectum NTCP differed by >5% for 10/19 patients and by >10% for 2/19 patients. For several patients, planned NTCP was less than the minimum or more than the maximum from the treatment course simulations. Conclusion: Treatment course simulations yield TCP values that are similar to planned values, while OAR NTCPs differ significantly

  16. Teriparatide promotes healing of critical size femur defect through accelerating angiogenesis and degradation of β-TCP in OVX osteoporotic rat model.

    PubMed

    Xie, Zhongjie; Weng, Sheji; Li, Hang; Yu, Xia; Lu, Shanshan; Huang, Kate; Wu, Zongyi; Bai, Bingli; Boodhun, Viraj; Yang, Lei

    2017-12-01

    Accumulating evidence suggests that early angiogenesis has an important effect on the healing of injury. Teriparatide (PTH) is extensively applied for its potent anabolic activity on bone, while little is known about its angiogenic ability which may facilitate new bone formation. In this study, we tested the angiogenic ability of PTH and its effect on degradation of β-tricalcium phosphate (β-TCP) in an ovariectomized (OVX) rat distal femoral metaphysis model. After successful establishment of the OVX model was confirmed, a critical size defect was drilled into each distal femur of the OVX rats. Afterwards all animals were randomly divided into three groups: control group, group β-TCP and group β-TCP+PTH, then rats of group β-TCP+PTH were injected Teriparatide (30 μg/kg) subcutaneous every other day. Four weeks after femur surgery, five specimens from each group were used for Microfil perfusion to reveal blood vessels in the bone defect. The residual rats were harvested for micro-computed tomography, histological analysis and immunochemistry. The results showed Teriparatide facilitated neovascularization, degradation of β-TCP and new bone formation in combination with β-TCP, which may be relevant to neovascularization in an early phase. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  17. In Vitro and In Vivo Dentinogenic Efficacy of Human Dental Pulp-Derived Cells Induced by Demineralized Dentin Matrix and HA-TCP.

    PubMed

    Kang, Kyung-Jung; Lee, Min Suk; Moon, Chan-Woong; Lee, Jae-Hoon; Yang, Hee Seok; Jang, Young-Joo

    2017-01-01

    Human dental pulp cells have been known to have the stem cell features such as self-renewal and multipotency. These cells are differentiated into hard tissue by addition of proper cytokines and biomaterials. Hydroxyapatite-tricalcium phosphates (HA-TCPs) are essential components of hard tissue and generally used as a biocompatible material in tissue engineering of bone. Demineralized dentin matrix (DDM) has been reported to increase efficiency of bone induction. We compared the efficiencies of osteogenic differentiation and in vivo bone formation of HA-TCP and DDM on human dental pulp stem cells (hDPSCs). DDM contains inorganic components as with HA-TCP, and organic components such as collagen type-1. Due to these components, osteoinduction potential of DDM on hDPSCs was remarkably higher than that of HA-TCP. However, the efficiencies of in vivo bone formation are similar in HA-TCP and DDM. Although osteogenic gene expression and bone formation in immunocompromised nude mice were similar levels in both cases, dentinogenic gene expression level was slightly higher in DDM transplantation than in HA-TCP. All these results suggested that in vivo osteogenic potentials in hDPSCs are induced with both HA-TCP and DDM by osteoconduction and osteoinduction, respectively. In addition, transplantation of hDPSCs/DDM might be more effective for differentiation into dentin.

  18. TCP Transcription Factors at the Interface between Environmental Challenges and the Plant’s Growth Responses

    PubMed Central

    Danisman, Selahattin

    2016-01-01

    Plants are sessile and as such their reactions to environmental challenges differ from those of mobile organisms. Many adaptions involve growth responses and hence, growth regulation is one of the most crucial biological processes for plant survival and fitness. The plant-specific TEOSINTE BRANCHED 1, CYCLOIDEA, PCF1 (TCP) transcription factor family is involved in plant development from cradle to grave, i.e., from seed germination throughout vegetative development until the formation of flowers and fruits. TCP transcription factors have an evolutionary conserved role as regulators in a variety of plant species, including orchids, tomatoes, peas, poplar, cotton, rice and the model plant Arabidopsis. Early TCP research focused on the regulatory functions of TCPs in the development of diverse organs via the cell cycle. Later research uncovered that TCP transcription factors are not static developmental regulators but crucial growth regulators that translate diverse endogenous and environmental signals into growth responses best fitted to ensure plant fitness and health. I will recapitulate the research on TCPs in this review focusing on two topics: the discovery of TCPs and the elucidation of their evolutionarily conserved roles across the plant kingdom, and the variety of signals, both endogenous (circadian clock, plant hormones) and environmental (pathogens, light, nutrients), TCPs respond to in the course of their developmental roles. PMID:28066483

  19. Development of PLGA-coated β-TCP scaffolds containing VEGF for bone tissue engineering.

    PubMed

    Khojasteh, Arash; Fahimipour, Farahnaz; Eslaminejad, Mohamadreza Baghaban; Jafarian, Mohammad; Jahangir, Shahrbanoo; Bastami, Farshid; Tahriri, Mohammadreza; Karkhaneh, Akbar; Tayebi, Lobat

    2016-12-01

    Bone tissue engineering is sought to apply strategies for bone defects healing without limitations and short-comings of using either bone autografts or allografts and xenografts. The aim of this study was to fabricate a thin layer poly(lactic-co-glycolic) acid (PLGA) coated beta-tricalcium phosphate (β-TCP) scaffold with sustained release of vascular endothelial growth factor (VEGF). PLGA coating increased compressive strength of the β-TCP scaffolds significantly. For in vitro evaluations, canine mesenchymal stem cells (cMSCs) and canine endothelial progenitor cells (cEPCs) were isolated and characterized. Cell proliferation and attachment were demonstrated and the rate of cells proliferation on the VEGF released scaffold was significantly more than compared to the scaffolds with no VEGF loading. A significant increase in expression of COL1 and RUNX2 was indicated in the scaffolds loaded with VEGF and MSCs compared to the other groups. Consequently, PLGA coated β-TCP scaffold with sustained and localized release of VEGF showed favourable results for bone regeneration in vitro, and this scaffold has the potential to use as a drug delivery device in the future. Copyright © 2016. Published by Elsevier B.V.

  20. Avoiding Biased-Feeding in the Scheduling of Collaborative Multipath TCP.

    PubMed

    Tsai, Meng-Hsun; Chou, Chien-Ming; Lan, Kun-Chan

    2016-01-01

    Smartphones have become the major communication and portable computing devices that access the Internet through Wi-Fi or mobile networks. Unfortunately, users without a mobile data subscription can only access the Internet at limited locations, such as hotspots. In this paper, we propose a collaborative bandwidth sharing protocol (CBSP) built on top of MultiPath TCP (MPTCP). CBSP enables users to buy bandwidth on demand from neighbors (called Helpers) and uses virtual interfaces to bind the subflows of MPTCP to avoid modifying the implementation of MPTCP. However, although MPTCP provides the required multi-homing functionality for bandwidth sharing, the current packet scheduling in collaborative MPTCP (e.g., Co-MPTCP) leads to the so-called biased-feeding problem. In this problem, the fastest link might always be selected to send packets whenever it has available cwnd, which results in other links not being fully utilized. In this work, we set out to design an algorithm, called Scheduled Window-based Transmission Control (SWTC), to improve the performance of packet scheduling in MPTCP, and we perform extensive simulations to evaluate its performance.

  1. Avoiding Biased-Feeding in the Scheduling of Collaborative Multipath TCP

    PubMed Central

    2016-01-01

    Smartphones have become the major communication and portable computing devices that access the Internet through Wi-Fi or mobile networks. Unfortunately, users without a mobile data subscription can only access the Internet at limited locations, such as hotspots. In this paper, we propose a collaborative bandwidth sharing protocol (CBSP) built on top of MultiPath TCP (MPTCP). CBSP enables users to buy bandwidth on demand from neighbors (called Helpers) and uses virtual interfaces to bind the subflows of MPTCP to avoid modifying the implementation of MPTCP. However, although MPTCP provides the required multi-homing functionality for bandwidth sharing, the current packet scheduling in collaborative MPTCP (e.g., Co-MPTCP) leads to the so-called biased-feeding problem. In this problem, the fastest link might always be selected to send packets whenever it has available cwnd, which results in other links not being fully utilized. In this work, we set out to design an algorithm, called Scheduled Window-based Transmission Control (SWTC), to improve the performance of packet scheduling in MPTCP, and we perform extensive simulations to evaluate its performance. PMID:27529783

  2. Leo Satellite Communication through a LEO Constellation using TCP/IP Over ATM

    NASA Technical Reports Server (NTRS)

    Foore, Lawrence R.; Konangi, Vijay K.; Wallett, Thomas M.

    1999-01-01

    The simulated performance characteristics for communication between a terrestrial client and a Low Earth Orbit (LEO) satellite server are presented. The client and server nodes consist of a Transmission Control Protocol /Internet Protocol (TCP/IP) over ATM configuration. The ATM cells from the client or the server are transmitted to a gateway, packaged with some header information and transferred to a commercial LEO satellite constellation. These cells are then routed through the constellation to a gateway on the globe that allows the client/server communication to take place. Unspecified Bit Rate (UBR) is specified as the quality of service (QoS). Various data rates are considered.

  3. Securing TCP/IP and Dial-up Access to Administrative Data.

    ERIC Educational Resources Information Center

    Conrad, L. Dean

    1992-01-01

    This article describes Arizona State University's solution to security risk inherent in general access systems such as TCP/IP (Transmission Control Protocol/INTERNET Protocol). Advantages and disadvantages of various options are compared, and the process of selecting a log-on authentication approach involving generation of a different password at…

  4. Silencing P2X7 receptor downregulates the expression of TCP-1 involved in lymphoma lymphatic metastasis

    PubMed Central

    Yang, Ziyi; Zeng, Jia; Zhang, Yi; Song, Yang; Kong, Ying; Ren, Shuangyi; Zuo, Yunfei

    2015-01-01

    P2X7R is an ATP-gated cation channel that participates in cell proliferation and apoptosis. TCP-1 assists with the protein folding. According to our previous research, the P2X7R has a potential role in P388D1 lymphoid neoplasm cells dissemination to peripheral lymph nodes. In order to make a further exploration about the probable mechanism, the lymph nodes which metastasized by P2X7R-silenced P388D1 cells or non-silenced cells were analyzed by 2DE and a MALDI-TOF-based proteomics approach. In the 64 proteins which were differentially expressed between two groups, TCP-1 was found to be significantly decreased in P2X7R shRNA group compared to controls. This correlation was also found in subsequent experiments in vivo and in vitro. The positive correlation between P2X7R and TCP-1 was also proved in both lymphoma and benign lymphadenopathy tissues from patients. It indicates that TCP-1 may be a crucial downstream molecular of P2X7R and plays a novel role in lymphoid neoplasm metastasis. PMID:26556873

  5. Silencing P2X7 receptor downregulates the expression of TCP-1 involved in lymphoma lymphatic metastasis.

    PubMed

    Jiang, Xudong; Mao, Wenjuan; Yang, Ziyi; Zeng, Jia; Zhang, Yi; Song, Yang; Kong, Ying; Ren, Shuangyi; Zuo, Yunfei

    2015-12-08

    P2X7R is an ATP-gated cation channel that participates in cell proliferation and apoptosis. TCP-1 assists with the protein folding. According to our previous research, the P2X7R has a potential role in P388D1 lymphoid neoplasm cells dissemination to peripheral lymph nodes. In order to make a further exploration about the probable mechanism, the lymph nodes which metastasized by P2X7R-silenced P388D1 cells or non-silenced cells were analyzed by 2DE and a MALDI-TOF-based proteomics approach. In the 64 proteins which were differentially expressed between two groups, TCP-1 was found to be significantly decreased in P2X7R shRNA group compared to controls. This correlation was also found in subsequent experiments in vivo and in vitro. The positive correlation between P2X7R and TCP-1 was also proved in both lymphoma and benign lymphadenopathy tissues from patients. It indicates that TCP-1 may be a crucial downstream molecular of P2X7R and plays a novel role in lymphoid neoplasm metastasis.

  6. Achieving QoS for TCP Traffic in Satellite Networks with Differentiated Services

    NASA Technical Reports Server (NTRS)

    Durresi, Arjan; Kota, Sastri; Goyal, Mukul; Jain, Raj; Bharani, Venkata

    2001-01-01

    Satellite networks play an indispensable role in providing global Internet access and electronic connectivity. To achieve such a global communications, provisioning of quality of service (QoS) within the advanced satellite systems is the main requirement. One of the key mechanisms of implementing the quality of service is traffic management. Traffic management becomes a crucial factor in the case of satellite network because of the limited availability of their resources. Currently, Internet Protocol (IP) only has minimal traffic management capabilities and provides best effort services. In this paper, we presented a broadband satellite network QoS model and simulated performance results. In particular, we discussed the TCP flow aggregates performance for their good behavior in the presence of competing UDP flow aggregates in the same assured forwarding. We identified several factors that affect the performance in the mixed environments and quantified their effects using a full factorial design of experiment methodology.

  7. Regulated expression of a novel TCP domain transcription factor indicates an involvement in the control of meristem activation processes in Solanum tuberosum.

    PubMed

    Faivre-Rampant, Odile; Bryan, Glenn J; Roberts, Alison G; Milbourne, Daniel; Viola, Roberto; Taylor, Mark A

    2004-04-01

    In this study, the aim was to determine whether TCP transcription factors are implicated in meristem activation in potato (Solanum tuberosum). By searching a database of potato EST sequences, with a sequence characteristically conserved in TCP domains, a potato tcp gene was identified. A BAC clone containing the tcp sequence was isolated and the genomic sequence was determined. Using a CAPS marker assay, the potato tcp gene (sttcp1) was mapped to chromosome 8. In dormant buds, relatively high levels of sttcp1-specific transcript were detected by in situ hybridization. By contrast, in sprouting buds, no expression of the sttcp1 could be detected. Furthermore, an inverse relationship between axillary bud size and the steady-state level of the sstcp1 transcript was demonstrated. In non-growing buds exhibiting correlative inhibition, sttcpI-specific transcript levels were also relatively high, but rapidly decreased when apical dominance was removed by excision of the apical bud.

  8. A comparative study of the proliferation and osteogenic differentiation of human periodontal ligament cells cultured on β-TCP ceramics and demineralized bone matrix with or without osteogenic inducers in vitro.

    PubMed

    An, Shaofeng; Gao, Yan; Huang, Xiangya; Ling, Junqi; Liu, Zhaohui; Xiao, Yin

    2015-05-01

    The repair of bone defects that result from periodontal diseases remains a clinical challenge for periodontal therapy. β-tricalcium phosphate (β-TCP) ceramics are biodegradable inorganic bone substitutes with inorganic components that are similar to those of bone. Demineralized bone matrix (DBM) is an acid-extracted organic matrix derived from bone sources that consists of the collagen and matrix proteins of bone. A few studies have documented the effects of DBM on the proliferation and osteogenic differentiation of human periodontal ligament cells (hPDLCs). The aim of the present study was to investigate the effects of inorganic and organic elements of bone on the proliferation and osteogenic differentiation of hPDLCs using three-dimensional porous β-TCP ceramics and DBM with or without osteogenic inducers. Primary hPDLCs were isolated from human periodontal ligaments. The proliferation of the hPDLCs on the scaffolds in the growth culture medium was examined using a Cell-Counting kit-8 (CCK-8) and scanning electron microscopy (SEM). Alkaline phosphatase (ALP) activity and the osteogenic differentiation of the hPDLCs cultured on the β-TCP ceramics and DBM were examined in both the growth culture medium and osteogenic culture medium. Specific osteogenic differentiation markers were examined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). SEM images revealed that the cells on the β-TCP were spindle-shaped and much more spread out compared with the cells on the DBM surfaces. There were no significant differences observed in cell proliferation between the β-TCP ceramics and the DBM scaffolds. Compared with the cells that were cultured on β-TCP ceramics, the ALP activity, as well as the Runx2 and osteocalcin (OCN) mRNA levels in the hPDLCs cultured on DBM were significantly enhanced both in the growth culture medium and the osteogenic culture medium. The organic elements of bone may exhibit greater osteogenic differentiation effects

  9. Microfibrous β-TCP/collagen scaffolds mimic woven bone in structure and composition.

    PubMed

    Zhang, Shen; Zhang, Xin; Cai, Qing; Wang, Bo; Deng, Xuliang; Yang, Xiaoping

    2010-12-01

    Woven bone, as the initial form of bone tissue, is always found in developing and repairing bone. It is thought of as a temporary scaffold for the deposition of osteogenic cells and the laying down of lamellar bone. Thus, we hypothesize that a matrix which resembles the architecture and components of woven bone can provide an osteoblastic microenvironment for bone cell growth and new bone formation. In this study, woven-bone-like beta-tricalcium phosphate (β-TCP)/collagen scaffolds were fabricated by sol-gel electrospinning and impregnating methods. Optimization studies on sol-gel synthesis and electrospinning process were conducted respectively to prepare pure β-TCP fibers with dimensions close to mineralized collagen fibrils in woven bone. The collagen-coating layer prepared by impregnation had an adhesive role that held the β-TCP fibers together, and resulted in rapid degradation and matrix mineralization in in vitro tests. MG63 osteoblast-like cells seeded on the resultant scaffolds showed three-dimensional (3D) morphologies, and merged into multicellular layers after 7 days culture. Cytotoxicity test further revealed that extracts from the resultant scaffolds could promote the proliferation of MG63 cells. Therefore, the woven-bone-like matrix that we constructed favored the attachment and proliferation of MG63 cells in three dimensions. It has great potential ability to shorten the time of formation of new bone.

  10. In Vitro and In Vivo Dentinogenic Efficacy of Human Dental Pulp-Derived Cells Induced by Demineralized Dentin Matrix and HA-TCP

    PubMed Central

    Kang, Kyung-Jung; Lee, Min Suk; Moon, Chan-Woong; Lee, Jae-Hoon

    2017-01-01

    Human dental pulp cells have been known to have the stem cell features such as self-renewal and multipotency. These cells are differentiated into hard tissue by addition of proper cytokines and biomaterials. Hydroxyapatite-tricalcium phosphates (HA-TCPs) are essential components of hard tissue and generally used as a biocompatible material in tissue engineering of bone. Demineralized dentin matrix (DDM) has been reported to increase efficiency of bone induction. We compared the efficiencies of osteogenic differentiation and in vivo bone formation of HA-TCP and DDM on human dental pulp stem cells (hDPSCs). DDM contains inorganic components as with HA-TCP, and organic components such as collagen type-1. Due to these components, osteoinduction potential of DDM on hDPSCs was remarkably higher than that of HA-TCP. However, the efficiencies of in vivo bone formation are similar in HA-TCP and DDM. Although osteogenic gene expression and bone formation in immunocompromised nude mice were similar levels in both cases, dentinogenic gene expression level was slightly higher in DDM transplantation than in HA-TCP. All these results suggested that in vivo osteogenic potentials in hDPSCs are induced with both HA-TCP and DDM by osteoconduction and osteoinduction, respectively. In addition, transplantation of hDPSCs/DDM might be more effective for differentiation into dentin. PMID:28761445

  11. A review on transport layer protocol performance for delivering video on an adhoc network

    NASA Astrophysics Data System (ADS)

    Suherman; Suwendri; Al-Akaidi, Marwan

    2017-09-01

    The transport layer protocol is responsible for the end to end data transmission. Transmission control protocol (TCP) provides a reliable connection and user datagram protocol (UDP) offers fast but unguaranteed data transfer. Meanwhile, the 802.11 (wireless fidelity/WiFi) networks have been widely used as internet hotspots. This paper evaluates TCP, TCP variants and UDP performances for video transmission on an adhoc network. The transport protocol - medium access cross-layer is proposed by prioritizing TCP acknowledgement to reduce delay. The NS-2 evaluations show that the average delays increase linearly for all the evaluated protocols and the average packet losses grow logarithmically. UDP produces the lowest transmission delay; 5.4% and 5.8% lower than TCP and TCP variant, but experiences the highest packet loss. Both TCP and TCP Vegas maintain packet loss as low as possible. The proposed cross-layer successfully decreases TCP and TCP Vegas delay about 0.12 % and 0.15%, although losses remain similar.

  12. Physico-Mechanical Properties of HA/TCP Pellets and Their Three-Dimensional Biological Evaluation In Vitro.

    PubMed

    Kamalaldin, Nurulain 'Atikah; Jaafar, Mariatti; Zubairi, Saiful Irwan; Yahaya, Badrul Hisham

    2018-01-04

    The use of bioceramics, especially the combination of hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP), as a three-dimensional scaffold in bone engineering is essential because together these elements constitute 60% of the bone content. Different ratios of HA and β-TCP were previously tested for their ability to produce suitable bioceramic scaffolds, which must be able to withstand high mechanical load. In this study, two ratios of HA/TCP (20:80 and 70:30) were used to create pellets, which then were evaluated in vitro to identify any adverse effects of using the material in bone grafting. Diametral tensile strength (DTS) and density testing was conducted to assess the mechanical strength and porosity of the pellets. The pellets then were tested for their toxicity to normal human fibroblast cells. In the toxicity assay, cells were incubated with the pellets for 3 days. At the end of the experiment, cell morphological changes were assessed, and the absorbance was read using PrestoBlue Cell Viability Reagent™. An inversely proportional relationship between DTS and porosity percentage was detected. Fibroblasts showed normal cell morphology in both treatments, which suggests that the HA/TCP pellets were not toxic. In the osteoblast cell attachment assay, cells were able to attach to the surface of both ratios, but cells were also able to penetrate inside the scaffold of the 70:30 pellets. This finding suggests that the 70:30 ratio had better osteoconduction properties than the 20:80 ratio.

  13. A Network Steganography Lab on Detecting TCP/IP Covert Channels

    ERIC Educational Resources Information Center

    Zseby, Tanja; Vázquez, Félix Iglesias; Bernhardt, Valentin; Frkat, Davor; Annessi, Robert

    2016-01-01

    This paper presents a network security laboratory to teach data analysis for detecting TCP/IP covert channels. The laboratory is mainly designed for students of electrical engineering, but is open to students of other technical disciplines with similar background. Covert channels provide a method for leaking data from protected systems, which is a…

  14. Interoperation of an UHF RFID Reader and a TCP/IP Device via Wired and Wireless Links

    PubMed Central

    Lee, Sang Hoon; Jin, Ik Soo

    2011-01-01

    A main application in radio frequency identification (RFID) sensor networks is the function that processes real-time tag information after gathering the required data from multiple RFID tags. The component technologies that contain an RFID reader, called the interrogator, which has a tag chip, processors, coupling antenna, and a power management system have advanced significantly over the last decade. This paper presents a system implementation for interoperation between an UHF RFID reader and a TCP/IP device that is used as a gateway. The proposed system consists of an UHF RFID tag, an UHF RFID reader, an RF end-device, an RF coordinator, and a TCP/IP I/F. The UHF RFID reader, operating at 915 MHz, is compatible with EPC Class-0/Gen1, Class-1/Gen1 and 2, and ISO18000-6B. In particular, the UHF RFID reader can be combined with the RF end-device/coordinator for a ZigBee (IEEE 802.15.4) interface, which is a low-power wireless standard. The TCP/IP device communicates with the RFID reader via wired links. On the other hand, it is connected to the ZigBee end-device via wireless links. The web based test results show that the developed system can remotely recognize information of multiple tags through the interoperation between the RFID reader and the TCP/IP device. PMID:22346665

  15. Interoperation of an UHF RFID reader and a TCP/IP device via wired and wireless links.

    PubMed

    Lee, Sang Hoon; Jin, Ik Soo

    2011-01-01

    A main application in radio frequency identification (RFID) sensor networks is the function that processes real-time tag information after gathering the required data from multiple RFID tags. The component technologies that contain an RFID reader, called the interrogator, which has a tag chip, processors, coupling antenna, and a power management system have advanced significantly over the last decade. This paper presents a system implementation for interoperation between an UHF RFID reader and a TCP/IP device that is used as a gateway. The proposed system consists of an UHF RFID tag, an UHF RFID reader, an RF end-device, an RF coordinator, and a TCP/IP I/F. The UHF RFID reader, operating at 915 MHz, is compatible with EPC Class-0/Gen1, Class-1/Gen1 and 2, and ISO18000-6B. In particular, the UHF RFID reader can be combined with the RF end-device/coordinator for a ZigBee (IEEE 802.15.4) interface, which is a low-power wireless standard. The TCP/IP device communicates with the RFID reader via wired links. On the other hand, it is connected to the ZigBee end-device via wireless links. The web based test results show that the developed system can remotely recognize information of multiple tags through the interoperation between the RFID reader and the TCP/IP device.

  16. Fabrication of 3D porous SF/β-TCP hybrid scaffolds for bone tissue reconstruction.

    PubMed

    Park, Hyun Jung; Min, Kyung Dan; Lee, Min Chae; Kim, Soo Hyeon; Lee, Ok Joo; Ju, Hyung Woo; Moon, Bo Mi; Lee, Jung Min; Park, Ye Ri; Kim, Dong Wook; Jeong, Ju Yeon; Park, Chan Hum

    2016-07-01

    Bio-ceramic is a biomaterial actively studied in the field of bone tissue engineering. But, only certain ceramic materials can resolve the corrosion problem and possess the biological affinity of conventional metal biomaterials. Therefore, the recent development of composites of hybrid composites and polymers has been widely studied. In this study, we aimed to select the best scaffold of silk fibroin and β-TCP hybrid for bone tissue engineering. We fabricated three groups of scaffold such as SF (silk fibroin scaffold), GS (silk fibroin/small granule size of β-TCP scaffold) and GM (silk fibroin/medium granule size of β-TCP scaffold), and we compared the characteristics of each group. During characterization of the scaffold, we used scanning electron microscopy (SEM) and a Fourier transform infrared spectroscopy (FTIR) for structural analysis. We compared the physiological properties of the scaffold regarding the swelling ratio, water uptake and porosity. To evaluate the mechanical properties, we examined the compressive strength of the scaffold. During in vitro testing, we evaluated cell attachment and cell proliferation (CCK-8). Finally, we confirmed in vivo new bone regeneration from the implanted scaffolds using histological staining and micro-CT. From these evaluations, the fabricated scaffold demonstrated high porosity with good inter-pore connectivity, showed good biocompatibility and high compressive strength and modulus. In particular, the present study indicates that the GM scaffold using β-TCP accelerates new bone regeneration of implanted scaffolds. Accordingly, our scaffold is expected to act a useful application in the field of bone tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1779-1787, 2016. © 2016 Wiley Periodicals, Inc.

  17. Effects of SiO2 and ZnO doping on mechanical and biological properties of 3D printed TCP scaffolds

    PubMed Central

    Fielding, Gary A.; Bandyopadhyay, Amit; Bose, Susmita

    2011-01-01

    Objectives To evaluate the effects of SiO2 (0.5 wt %) and ZnO (0.25 wt %) dopants on the mechanical and biological properties of tricalcium phosphate (TCP) scaffolds with three dimensionally (3D) interconnected pores. Methods Scaffolds were created with a commercial 3D printer. Post sintering phase analysis was determined by x-ray diffraction. Surface morphology of the scaffolds was examined by field emission electron microscopy. Mechanical strength was evaluated with a screw driven universal testing machine. MTT assay was used for cellular proliferation characteristics and cellular morphology was examined by field emission electron microscopy. Results Addition of dopants into TCP increased the average density of pure TCP from 90.8 ± 0.8% to 94.1 ± 1.6% and retarded the β to α phase transformation at high sintering temperatures, which resulted in up to 2.5 fold increase in compressive strength. In vitro cell-materials interaction studies, carried out using hFOB cells, confirmed that the addition of SiO2 and ZnO to the scaffolds facilitates faster cell proliferation when compared to pure TCP scaffolds. Significance Addition of SiO2 and ZnO dopants to the TCP scaffolds showed increased mechanical strength as well as increased cellular proliferation. PMID:22047943

  18. GATEWAY - COMMUNICATIONS GATEWAY SOFTWARE FOR NETEX, DECNET, AND TCP/IP

    NASA Technical Reports Server (NTRS)

    Keith, B.

    1994-01-01

    of bytes contained in each ransferred data packet. If GATEWAY detects an error during the data transfer, the sessions on both networks are terminated and the passive offer on the appropriate network is reissued. After performing the desired data transfer, one of the remote applications will send a network disconnect to the gateway to close its communication link. Upon detecting this network disconnect, GATEWAY replies with its own disconnect to ensure that the network connection has been fully terminated. Then, GATEWAY terminates its session with the other application by closing the communication link. GATEWAY has been implemented on a DEC VAX under VMS 4.7. It is written in ADA and has a central memory requirement of approximately 406K bytes. The communications protocols supported by GATEWAY are Network Systems Corporation's Network Executive (NETEX), Excelan's TCP/IP, and DECnet. GATEWAY was developed in 1988.

  19. High-dispersion spectroscopy of the probable microlensing event TCP J05074264+2447555

    NASA Astrophysics Data System (ADS)

    Maehara, Hiroyuki

    2017-11-01

    We report the spectroscopic observation of TCP J05074264+2447555 which was discovered by Tadashi Kojima at 10.8 mag on 2017-10-31.7340 (http://www.cbat.eps.harvard.edu/unconf/followups/J05074264+2447555.html).

  20. Size versus electronic factors in transition metal carbide and TCP phase stability

    NASA Astrophysics Data System (ADS)

    Pettifor, D. G.; Seiser, B.; Margine, E. R.; Kolmogorov, A. N.; Drautz, R.

    2013-09-01

    The contributions of atomic size and electronic factors to the structural stability of transition metal carbides and topologically close-packed (TCP) phases are investigated. The hard-sphere model that has been used by Cottrell to rationalize the occurrence of the octahedral and trigonal local coordination polyhedra within the transition metal carbides is shown to have limitations in TiC since density functional theory (DFT) predicts that the second most metastable phase closest to the B1 (NaCl) ground state takes the B? (BN) structure type with 5-atom local coordination polyhedra with very short Ti-C bond lengths. The importance of electronic factors in the TCP phases is demonstrated by DFT predictions that the A15, ? and ? phases are stabilized between groups VI and VII of the elemental transition metals, whereas the ? and Laves phases are destabilized. The origin of this difference is related to the bimodal shape parameter of the electronic density of states by using the bond-order potential expansion of the structural energy within a canonical tight-binding model. The importance of the size factor in the TCP phases is illustrated by the DFT heats of formation for the binary systems Mo-Re, Mo-Ru, Nb-Re and Nb-Ru which show that the ? and Laves phases become more and more stable compared to A15, ? and ? as the size factor increases from Mo-Re through to Nb-Ru.

  1. Secretion of TcpF by the Vibrio cholerae Toxin-Coregulated Pilus Biogenesis Apparatus Requires an N-Terminal Determinant

    PubMed Central

    Megli, Christina J.

    2013-01-01

    Type IV pili are important for microcolony formation, biofilm formation, twitching motility, and attachment. We and others have shown that type IV pili are important for protein secretion across the outer membrane, similar to type II secretion systems. This study explored the relationship between protein secretion and pilus formation in Vibrio cholerae. The toxin-coregulated pilus (TCP), a type IV pilus required for V. cholerae pathogenesis, is necessary for the secretion of the colonization factor TcpF (T. J. Kirn, N. Bose, and R. K. Taylor, Mol. Microbiol. 49:81–92, 2003). This phenomenon is not unique to V. cholerae; secreted virulence factors that are dependent on the presence of components of the type IV pilus biogenesis apparatus for secretion have been reported with Dichelobacter nodosus (R. M. Kennan, O. P. Dhungyel, R. J. Whittington, J. R. Egerton, and J. I. Rood, J. Bacteriol. 183:4451–4458, 2001) and Francisella tularensis (A. J. Hager et al., Mol. Microbiol. 62:227–237, 2006). Using site-directed mutagenesis, we demonstrated that the secretion of TcpF is dependent on the presence of selected amino acid R groups at position five. We were unable to find other secretion determinants, suggesting that Y5 is the major secretion determinant within TcpF. We also report that proteins secreted in a type IV pilus biogenesis apparatus-dependent manner have a YXS motif within the first 15 amino acids following the Sec cleavage site. The YXS motif is not present in proteins secreted by type II secretion systems, indicating that this is unique to type IV pilus-mediated secretion. Moreover, we show that TcpF interacts with the pilin TcpA, suggesting that these proteins are secreted by the type IV pilus biogenesis system. These data provide a starting point for understanding how type IV pili can mediate secretion of virulence factors important for bacterial pathogenesis. PMID:23564177

  2. Communication-Gateway Software For NETEX, DECnet, And TCP/IP

    NASA Technical Reports Server (NTRS)

    Keith, B.; Ferry, D.; Fendler, E.

    1990-01-01

    Communications gateway software, GATEWAY, provides process-to-process communication between remote applications programs in different protocol domains. Communicating peer processes may be resident on any paired combination of NETEX, DECnet, or TCP/IP hosts. Provides necessary mapping from one protocol to another and facilitates practical intermachine communications in cost-effective manner by eliminating need to standardize on single protocol or to implement multiple protocols in host computers. Written in Ada.

  3. Histochemical examination of adipose derived stem cells combined with β-TCP for bone defects restoration under systemic administration of 1α,25(OH)2D3.

    PubMed

    Feng, Wei; Lv, Shengyu; Cui, Jian; Han, Xiuchun; Du, Juan; Sun, Jing; Wang, Kefeng; Wang, Zhenming; Lu, Xiong; Guo, Jie; Oda, Kimimitsu; Amizuka, Norio; Xu, Xin; Li, Minqi

    2015-09-01

    The purpose of this study was to evaluate the effects of osteogenic differentiated adipose-derived stem cell (ADSC) loaded beta-tricalcium phosphate (β-TCP) in the restoration of bone defects under intraperitoneal administration of 1α,25-dihydroxyvitamin D3(1α,25(OH)2D3). ADSCs were isolated from the fat tissue of 8 week old Wister rats and co-cultured with β-TCP for 21 days under osteogenic induction. Then the ADSC-β-TCP complexes were implanted into bone defects in the femora of rats. 1α,25(OH)2D3 (VD) or normal saline (NS) was administrated intraperitoneally every other day after the surgery. Femora were harvested at day 7, day 14 and day 28 post-surgery. There were 4 groups for all specimens: β-TCP-NS group; β-TCP-ADSC-NS group; β-TCP-VD group and β-TCP-ADSC-VD group. Alkaline phosphatase (ALP) was up-regulated obviously in ADSC groups compared with non-ADSC groups at day 7, day 14 and day 28, although high expression of runt-related transcription factor 2 (RUNX2) was only seen at day 7. Furthermore, the number of TRAP-positive osteoclasts and the expression of cathepsin K (CK) were significantly decreased in VD groups compared with non-VD groups at day 7 and day 14. As a most significant finding, the β-TCP-ADSC-VD group showed the highest BV/TV ratio compared with the other three groups at day 28. Taken together, ADSC-loaded β-TCP under the administration of 1α,25(OH)2D3 made a promising therapy for bone defects restoration. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Hydrogel-beta-TCP scaffolds and stem cells for tissue engineering bone.

    PubMed

    Weinand, Christian; Pomerantseva, Irina; Neville, Craig M; Gupta, Rajiv; Weinberg, Eli; Madisch, Ijad; Shapiro, Frederic; Abukawa, Harutsugi; Troulis, Maria J; Vacanti, Joseph P

    2006-04-01

    Trabecular bone is a material of choice for reconstruction after trauma and tumor resection and for correction of congenital defects. Autologous bone grafts are available in limited shapes and sizes; significant donor site morbidity is another major disadvantage to this approach. To overcome these limitations, we used a tissue engineering approach to create bone replacements in vitro, combining bone-marrow-derived differentiated mesenchymal stem cells (MSCs) suspended in hydrogels and 3-dimensionally printed (3DP) porous scaffolds made of beta-tricalcium-phosphate (beta-TCP). The scaffolds provided support for the formation of bone tissue in collagen I, fibrin, alginate, and pluronic F127 hydrogels during culturing in oscillating and rotating dynamic conditions. Histological evaluation including toluidine blue, alkaline phosphatase, and von Kossa staining was done at 1, 2, 4, and 6 weeks. Radiographic evaluation and high-resolution volumetric CT (VCT) scanning, expression of bone-specific genes and biomechanical compression testing were performed at 6 weeks. Both culture conditions resulted in similar bone tissue formation. Histologically collagen I and fibrin hydrogels specimens had superior bone tissue, although radiopacities were detected only in collagen I samples. VCT scan revealed density values in all but the Pluronic F127 samples, with Houndsfield unit values comparable to native bone in collagen I and fibrin glue samples. Expression of bone-specific genes was significantly higher in the collagen I samples. Pluronic F127 hydrogel did not support formation of bone tissue. All samples cultured in dynamic oscillating conditions had slightly higher mechanical strength than under rotating conditions. Bone tissue can be successfully formed in vitro using constructs comprised of collagen I hydrogel, MSCs, and porous beta-TCP scaffolds.

  5. Preparation and characterization of gelatin-chitosan-nanoβ-TCP based scaffold for orthopaedic application.

    PubMed

    Maji, Kanchan; Dasgupta, Sudip; Pramanik, Krishna; Bissoyi, Akalabya

    2018-05-01

    The primary aim of this study was to fabricate gelatin/chitosan/β-TCP (GCT) composite scaffold to improve its compressive mechanical behaviour and in-vivo biocompatibility with predictable degradation rate. Beta tricalcium phosphate (β-TCP) powder was synthesized in size range between 70-100 nm using aqueous precipitation route at a fixed Ca/P molar ratio of 1.5:1 at pH 10 and after subsequent heat treatment of as precipitated powder at 800 °C for 4 hours. The composite scaffolds were fabricated using solid-liquid phase separation of the slurry containing gelatin, chitosan, β-tricalcium phosphate in varying proportion and subsequent lyophilisation of the phase separated mixture. The prepared scaffolds exhibited high porosity (>80%) with pore sizes ranging between 78-382 μm as determined using Hg-porosimetry. SEM result revealed that incorporation of β-TCP to the extent of 30 wt% resulted in well-shaped and uniformly distributed interconnected pores of average pore size of 120 ± 18.6 μm in it. Compressive strength of the scaffolds was increased from 0.8 MPa to 2.45 MPa on increase in β-TCP content from 10 wt%-30 wt% in the prepared scaffold. Human Umbilical Cord derived mesenchymal stem cells (MSCs) exhibited higher degree of lamellopodia and fillopodia extensions and better spreading behaviour onto GCT30 scaffold. MTT assay and immunocytochemistry studies with cultured MSCs revealed that GCT30 scaffolds were more conducive to MSC's proliferation and differentiation into osteoblast lineage. In vivo implantation of GCT30 scaffold subcutaneously into mice did not indicate any significant inflammatory reaction, but ongoing vascularization. Copyright © 2018. Published by Elsevier B.V.

  6. On the radiobiological impact of metal artifacts in head-and-neck IMRT in terms of tumor control probability (TCP) and normal tissue complication probability (NTCP).

    PubMed

    Kim, Yusung; Tomé, Wolfgang A

    2007-11-01

    To investigate the effects of distorted head-and-neck (H&N) intensity-modulated radiation therapy (IMRT) dose distributions (hot and cold spots) on normal tissue complication probability (NTCP) and tumor control probability (TCP) due to dental-metal artifacts. Five patients' IMRT treatment plans have been analyzed, employing five different planning image data-sets: (a) uncorrected (UC); (b) homogeneous uncorrected (HUC); (c) sinogram completion corrected (SCC); (d) minimum-value-corrected (MVC); and (e) streak-artifact-reduction including minimum-value-correction (SAR-MVC), which has been taken as the reference data-set. The effects on NTCP and TCP were evaluated using the Lyman-NTCP model and the Logistic-TCP model, respectively. When compared to the predicted NTCP obtained using the reference data-set, the treatment plan based on the original CT data-set (UC) yielded an increase in NTCP of 3.2 and 2.0% for the spared parotid gland and the spinal cord, respectively. While for the treatment plans based on the MVC CT data-set the NTCP increased by a 1.1% and a 0.1% for the spared parotid glands and the spinal cord, respectively. In addition, the MVC correction method showed a reduction in TCP for target volumes (MVC: delta TCP = -0.6% vs. UC: delta TCP = -1.9%) with respect to that of the reference CT data-set. Our results indicate that the presence of dental-metal-artifacts in H&N planning CT data-sets has an impact on the estimates of TCP and NTCP. In particular dental-metal-artifacts lead to an increase in NTCP for the spared parotid glands and a slight decrease in TCP for target volumes.

  7. Genome-Wide Identification of TCP Family Transcription Factors in Medicago truncatula Reveals Significant Roles of miR319-Targeted TCPs in Nodule Development

    PubMed Central

    Wang, Hongfeng; Wang, Hongwei; Liu, Rong; Xu, Yiteng; Lu, Zhichao; Zhou, Chuanen

    2018-01-01

    TCP proteins, the plant-specific transcription factors, are involved in the regulation of multiple aspects of plant development among different species, such as leaf development, branching, and flower symmetry. However, thus far, the roles of TCPs in legume, especially in nodulation are still not clear. In this study, a genome-wide analysis of TCP genes was carried out to discover their evolution and function in Medicago truncatula. In total, 21 MtTCPs were identified and classified into class I and class II, and the class II MtTCPs were further divided into two subclasses, CIN and CYC/TB1. The expression profiles of MtTCPs are dramatically different. The universal expression of class I MtTCPs was detected in all organs. However, the MtTCPs in CIN subclass were highly expressed in leaf and most of the members in CYC/TB1 subclass were highly expressed in flower. Such organ-specific expression patterns of MtTCPs suggest their different roles in plant development. In addition, most MtTCPs were down-regulated during the nodule development, except for the putative MtmiR319 targets, MtTCP3, MtTCP4, and MtTCP10A. Overexpression of MtmiR319A significantly reduced the expression level of MtTCP3/4/10A/10B and resulted in the decreased nodule number, indicating the important roles of MtmiR319-targeted MtTCPs in nodulation. Taken together, this study systematically analyzes the MtTCP gene family at a genome-wide level and their possible functions in nodulation, which lay the basis for further explorations of MtmiR319/MtTCPs module in association with nodule development in M. truncatula.

  8. The TIE1 Transcriptional Repressor Links TCP Transcription Factors with TOPLESS/TOPLESS-RELATED Corepressors and Modulates Leaf Development in Arabidopsis[W

    PubMed Central

    Tao, Qing; Guo, Dongshu; Wei, Baoye; Zhang, Fan; Pang, Changxu; Jiang, Hao; Zhang, Jinzhe; Wei, Tong; Gu, Hongya; Qu, Li-Jia; Qin, Genji

    2013-01-01

    Leaf size and shape are mainly determined by coordinated cell division and differentiation in lamina. The CINCINNATA (CIN)-like TEOSINTE BRANCHED1/CYCLOIDEA/PCF (TCP) transcription factors are key regulators of leaf development. However, the mechanisms that control TCP activities during leaf development are largely unknown. We identified the TCP Interactor containing EAR motif protein1 (TIE1), a novel transcriptional repressor, as a major modulator of TCP activities during leaf development. Overexpression of TIE1 leads to hyponastic and serrated leaves, whereas disruption of TIE1 causes epinastic leaves. TIE1 is expressed in young leaves and encodes a transcriptional repressor containing a C-terminal EAR motif, which mediates interactions with the TOPLESS (TPL)/TOPLESS-RELATED (TPR) corepressors. In addition, TIE1 physically interacts with CIN-like TCPs. We propose that TIE1 regulates leaf size and morphology by inhibiting the activities of TCPs through recruiting the TPL/TPR corepressors to form a tertiary complex at early stages of leaf development. PMID:23444332

  9. Effect of citric acid on setting reaction and tissue response to β-TCP granular cement.

    PubMed

    Fukuda, Naoyuki; Tsuru, Kanji; Mori, Yoshihide; Ishikawa, Kunio

    2017-02-24

    We recently reported that when an acidic calcium phosphate solution is mixed with β-tricalcium phosphate (β-TCP) granules, the resulting dicalcium phosphate dihydrate (DCPD) crystals form bridges between the β-TCP granules, creating a set interconnected porous structure in approximately 1 min. Although this self-setting β-TCP granular cement (β-TCPGC) is useful for clinical applications, the short setting time is a key drawback for handling. In this study, the setting time of β-TCPGC was adjusted with the addition of citric acid, which is a known inhibiter of DCPD crystal growth. As the concentration of citric acid in the acidic calcium phosphate solution increased, the amount of DCPD formation in the set β-TCPGC decreased, and the crystal morphology of DCPD became elongated. β-TCPGC prepared with various citric acid concentrations were used as grafting material in rat calvarial bone defects to evaluate bone regeneration in vivo. Four weeks after implantation, no inflammatory reaction and approximately 20% new bone formation were observed, regardless of the presence or absence of citric acid in the liquid phase of β-TCPGC. We concluded, therefore, that citric acid might be a useful retarder of β-TCPGC setting times.

  10. Response of human dental pulp cells to a silver-containing PLGA/TCP-nanofabric as a potential antibacterial regenerative pulp-capping material.

    PubMed

    Cvikl, Barbara; Hess, Samuel C; Miron, Richard J; Agis, Hermann; Bosshardt, Dieter; Attin, Thomas; Schmidlin, Patrick R; Lussi, Adrian

    2017-02-27

    Damage or exposure of the dental pulp requires immediate therapeutic intervention. This study assessed the biocompatibility of a silver-containing PLGA/TCP-nanofabric scaffold (PLGA/Ag-TCP) in two in vitro models, i.e. the material adapted on pre-cultured cells and cells directly cultured on the material, respectively. Collagen saffolds with and without hyaluronan acid (Coll-HA; Coll) using both cell culturing methods and cells growing on culture plates served as reference. Cell viability and proliferation were assessed after 24, 48, and 72 h based on formazan formation and BrdU incorporation. Scaffolds were harvested. Gene expression of interleukin(IL)-6, tumor necrosis factor (TNF)-alpha, and alkaline phosphatase (AP) was assessed 24 h after stimulation. In both models formazan formation and BrdU incorporation was reduced by PLGA/Ag-TCP on dental pulp cells, while no significant reduction was found in cells with Coll and Coll-HA. Cells with PLGA/Ag-TCP for 72 h showed similar relative BrdU incorporation than cells stimulated with Coll and Coll-HA. A prominent increase in the pro-inflammatory genes IL-6 and TNF-α was observed when cells were cultured with PLGA/Ag-TCP compared to the other groups. This increase was parallel with a slight increase in AP expression. Overall, no differences between the two culture methods were observed. PLGA/Ag-TCP decreased viability and proliferation rate of human dental pulp cells and increased the pro-inflammatory capacity and alkaline phosphatase expression. Whether these cellular responses observed in vitro translate into pulp regeneration in vivo will be assessed in further studies.

  11. Spectroscopic classification of TCP J17140253-2849233 as a Galactic nova

    NASA Astrophysics Data System (ADS)

    Williams, S. C.; Darnley, M. J.; Healy, M. W.

    2018-03-01

    We obtained a spectrum of TCP J17140253-2849233 (see CBAT TOCP, also designated PNV J17140261-2849237) using the FRODOSpec spectrograph (Barnsley et al. 2012) on the 2-m Liverpool Telescope (Steele et al. 2004), with a wavelength coverage of 3900 to 5100 & Aring; and 5900 to 8000 & Aring; and resolution of R 5400.

  12. Chiba Tendril-Less locus determines tendril organ identity in melon (Cucumis melo L.) and potentially encodes a tendril-specific TCP homolog.

    PubMed

    Mizuno, Shinji; Sonoda, Masatoshi; Tamura, Yayoi; Nishino, Eisho; Suzuki, Hideyuki; Sato, Takahide; Oizumi, Toshikatsu

    2015-11-01

    Tendrils are filamentous plant organs that coil on contact with an object, thereby providing mechanical support for climbing to reach more sunlight. Plant tendrils are considered to be modified structure of leaves, stems, or inflorescence, but the origin of cucurbit tendrils is still argued because of the complexity in the axillary organ patterning. We carried out morphological and genetic analyses of the Chiba Tendril-Less (ctl) melon (Cucumis melo) mutant, and found strong evidence that the melon tendril is a modified organ derived from a stem-leaf complex of a lateral shoot. Heterozygous (CTL/ctl) plants showed traits intermediate between tendril and shoot, and ontogenies of wild-type tendrils and mutant modified shoots coincided. We identified the CTL locus in a 200-kb region in melon linkage group IX. A single base deletion in a melon TCP transcription factor gene (CmTCP1) was detected in the mutant ctl sequence, and the expression of CmTCP1 was specifically high in wild-type tendrils. Phylogenetic analysis demonstrated the novelty of the CmTCP1 protein and the unique molecular evolution of its orthologs in the Cucurbitaceae. Our results move us closer to answering the long-standing question of which organ was modified to become the cucurbit tendril, and suggest a novel function of the TCP transcription factor in plant development.

  13. An AT-hook protein DEPRESSED PALEA1 physically interacts with the TCP Family transcription factor RETARDED PALEA1 in rice.

    PubMed

    Yin, Dedong; Liu, Xue; Shi, Zhenying; Li, Dayong; Zhu, Lihuang

    2018-01-01

    The cereal crops (such as rice and maize) which belong to the grass family, are the most important grain crops for human beings, and the development of their flower and inflorescence architecture has attracted extensive attention. Although multiple genes involved in the regulation of floral and inflorescence organogenesis have been identified, the underlying molecular mechanisms are largely unknown. Previously, we identified rice depressed palea1 (dp1) mutants with defects in main structure of palea and its enhancer RETARDED PALEA1 (REP1). DP1 is an AT-hook protein while REP1 is a TCP transcription factor, both of which are important regulators of palea development. However, the relationship of these two proteins has not been elucidated yet. Here, we demonstrated that DP1 interacts physically with REP1 both in yeast and in rice protoplasts. Considering the close phylogenetic relationship between maize and rice, we further hypothesize that their orthologs in maize, BARREN STALK FASTIGIATE (BAF1) and BRANCH ANGLE DEFECTIVE 1 (BAD1), may interact physically. Subsequently, we verified their physical interaction, indicating that the interaction between AT-hook proteins and TCP proteins is conserved in rice and maize. Our findings may reveal a novel molecular mechanism of floral and inflorescence development in grasses. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. ASAS-SN Confirmation of the Bright Microlensing Event TCP J05074264+2447555

    NASA Astrophysics Data System (ADS)

    Jayasinghe, T.; Dong, Subo; Stanek, K. Z.; Kochanek, C. S.; Thompson, T. A.; Prieto, J. L.; Shappee, B. J.; Holoien, T. W.-S.

    2017-11-01

    The transient TCP J05074264+2447555 was first discovered by T. Kojima on UT 2017-10-25.688. The ASAS-SN Sky Patrol light curve (Shappee et al. 2014; Kochanek et al. 2017) and follow-up spectroscopy (ATel #10919) suggested this to be a probable microlensing event.

  15. Activation of YUCCA5 by the Transcription Factor TCP4 Integrates Developmental and Environmental Signals to Promote Hypocotyl Elongation in Arabidopsis.

    PubMed

    Challa, Krishna Reddy; Aggarwal, Pooja; Nath, Utpal

    2016-09-05

    Cell expansion is an essential process in plant morphogenesis and is regulated by the coordinated action of environmental stimuli and endogenous factors, such as the phytohormones auxin and brassinosteroid. Although the biosynthetic pathways that generate these hormones and their downstream signaling mechanisms have been extensively studied, the upstream transcriptional network that modulates their levels and connects their action to cell morphogenesis is less clear. Here we show that the miR319-regulated TCP (TEOSINTE BRANCHED 1, CYCLODEA, PROLIFERATING CELL FACTORS) transcription factors, notably TCP4, directly activate YUCCA5 transcription and integrate the auxin response to a brassinosteroid-dependent molecular circuit that promotes cell elongation in Arabidopsis hypocotyls. Further, TCP4 modulates the common transcriptional network downstream to auxin-BR signaling, which is also triggered by environmental cues, such as light, to promote cell expansion. Our study links TCP function with the hormone response during cell morphogenesis and shows that developmental and environmental signals converge on a common transcriptional network to promote cell elongation. {copyright, serif} 2016 American Society of Plant Biologists. All rights reserved.

  16. Internet Protocol Enhanced over Satellite Networks

    NASA Technical Reports Server (NTRS)

    Ivancic, William D.

    1999-01-01

    Extensive research conducted by the Satellite Networks and Architectures Branch of the NASA Lewis Research Center led to an experimental change to the Internet's Transmission Control Protocol (TCP) that will increase performance over satellite channels. The change raises the size of the initial burst of data TCP can send from 1 packet to 4 packets or roughly 4 kilobytes (kB), whichever is less. TCP is used daily by everyone on the Internet for e-mail and World Wide Web access, as well as other services. TCP is one of the feature protocols used in computer communications for reliable data delivery and file transfer. Increasing TCP's initial data burst from the previously specified single segment to approximately 4 kB may improve data transfer rates by up to 27 percent for very small files. This is significant because most file transfers in wide-area networks today are small files, 4 kilobytes or less. In addition, because data transfers over geostationary satellites can take 5 to 20 times longer than over typical terrestrial connections, increasing the initial burst of data that can be sent is extremely important. This research along with research from other institutions has led to the release of two new Request for Comments from the Internet Engineering Task Force (IETF, the international body that sets Internet standards). In addition, two studies of the implications of this mechanism were also funded by NASA Lewis.

  17. Expression of a repressor form of the Arabidopsis thaliana transcription factor TCP16 induces the formation of ectopic meristems.

    PubMed

    Uberti-Manassero, Nora G; Coscueta, Ezequiel R; Gonzalez, Daniel H

    2016-11-01

    Plants that express a fusion of the Arabidopsis thaliana class I TCP transcription factor TCP16 to the EAR repressor domain develop several phenotypic alterations, including rounder leaves, short petioles and pedicels, and delayed elongation of sepals, petals and anthers. In addition, these plants develop lobed cotyledons and ectopic meristems. Ectopic meristems are formed on the adaxial side of cotyledon petioles and arise from a cleft that is formed at this site. Analysis of the expression of reporter genes indicated that meristem genes are reactivated at the site of emergence of ectopic meristems, located near the bifurcation of cotyledon veins. The plants also show increased transcript levels of the boundary-specific CUP-SHAPED COTYLEDON (CUC) genes. The results suggest that TCP16 is able to modulate the induction of meristematic programs and the differentiation state of plant cells. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  18. Feasibility of TCP-based dose painting by numbers applied to a prostate case with (18)F-choline PET imaging.

    PubMed

    Dirscherl, Thomas; Rickhey, Mark; Bogner, Ludwig

    2012-02-01

    A biologically adaptive radiation treatment method to maximize the TCP is shown. Functional imaging is used to acquire a heterogeneous dose prescription in terms of Dose Painting by Numbers and to create a patient-specific IMRT plan. Adapted from a method for selective dose escalation under the guidance of spatial biology distribution, a model, which translates heterogeneously distributed radiobiological parameters into voxelwise dose prescriptions, was developed. At the example of a prostate case with (18)F-choline PET imaging, different sets of reported values for the parameters were examined concerning their resulting range of dose values. Furthermore, the influence of each parameter of the linear-quadratic model was investigated. A correlation between PET signal and proliferation as well as cell density was assumed. Using our in-house treatment planning software Direct Monte Carlo Optimization (DMCO), a treatment plan based on the obtained dose prescription was generated. Gafchromic EBT films were irradiated for evaluation. When a TCP of 95% was aimed at, the maximal dose in a voxel of the prescription exceeded 100Gy for most considered parameter sets. One of the parameter sets resulted in a dose range of 87.1Gy to 99.3Gy, yielding a TCP of 94.7%, and was investigated more closely. The TCP of the plan decreased to 73.5% after optimization based on that prescription. The dose difference histogram of optimized and prescribed dose revealed a mean of -1.64Gy and a standard deviation of 4.02Gy. Film verification showed a reasonable agreement of planned and delivered dose. If the distribution of radiobiological parameters within a tumor is known, this model can be used to create a dose-painting by numbers plan which maximizes the TCP. It could be shown, that such a heterogeneous dose distribution is technically feasible. Copyright © 2012. Published by Elsevier GmbH.

  19. A TCP domain transcription factor controls flower type specification along the radial axis of the Gerbera (Asteraceae) inflorescence.

    PubMed

    Broholm, Suvi K; Tähtiharju, Sari; Laitinen, Roosa A E; Albert, Victor A; Teeri, Teemu H; Elomaa, Paula

    2008-07-01

    Several key processes in plant development are regulated by TCP transcription factors. CYCLOIDEA-like (CYC-like) TCP domain proteins have been shown to control flower symmetry in distantly related plant lineages. Gerbera hybrida, a member of one of the largest clades of angiosperms, the sunflower family (Asteraceae), is an interesting model for developmental studies because its elaborate inflorescence comprises different types of flowers that have specialized structures and functions. The morphological differentiation of flower types involves gradual changes in flower size and symmetry that follow the radial organization of the densely packed inflorescence. Differences in the degree of petal fusion further define the distinct shapes of the Gerbera flower types. To study the role of TCP transcription factors during specification of this complex inflorescence organization, we characterized the CYC-like homolog GhCYC2 from Gerbera. The expression of GhCYC2 follows a gradient along the radial axis of the inflorescence. GhCYC2 is expressed in the marginal, bilaterally symmetrical ray flowers but not in the centermost disk flowers, which are nearly radially symmetrical and have significantly less fused petals. Overexpression of GhCYC2 causes disk flowers to obtain morphologies similar to ray flowers. Both expression patterns and transgenic phenotypes suggest that GhCYC2 is involved in differentiation among Gerbera flower types, providing the first molecular evidence that CYC-like TCP factors take part in defining the complex inflorescence structure of the Asteraceae, a major determinant of the family's evolutionary success.

  20. Paradoxical tunnel enlargement after ACL reconstruction with hamstring autografts when using β-TCP containing interference screws for tibial aperture fixation- prospectively comparative study.

    PubMed

    Wang, Joon Ho; Lee, Eun Su; Lee, Byung Hoon

    2017-09-16

    Tibial aperture fixation with a bioabsorbable interference screw is a popular fixation method in anterior cruciate ligament reconstruction (ACLR). An interference screw containing β-tricalcium phosphate (β-TCP) to improve bony integration and biocompatibility was recently introduced. This study aims to compare the clinical outcomes and radiological results of tunnel enlargement effect between the 2 bioabsorbable fixative devices of pure poly-L-lactic acid (PLLA) interference screws and β-TCP-containing screws, for tibial interference fixation in ACLR using hamstring autografts. Eighty consecutive patients who had undergone double-bundle ACLR between 2011 to 2012 were prospectively reviewed and randomly divided into two groups based on the type of tibial interference screw: 28 were assigned to the pure PLLA screw group (Group A), while the other 29 were assigned to the β-TCP-containing screw fixation group (Group B). Clinical evaluations and radiological analyses were conducted in both groups with a minimum 2- year follow-up. There was no significant difference in subjective or objective clinical outcome between the 2 groups. In radiological analyses, the use of a β-TCP-containing screw reduced tunnel widening in the portion of the tunnel with screw engagement compared to the pure PLLA screw, while the use of a β-TCP-containing screw resulted in greater tunnel enlargement in the proximal portion of the tunnel without screw engagement than use of a pure PLLA screw. Use of a β-TCP-containing interference screw in tibial aperture fixation reduced tunnel enlargement in the vicinity of the screw, whereas greater enlargement occurred proximal to the screw end relative to use of a pure PLLA interference screw. These paradoxical enlargements in use of β-TCP containing screws suggest that for reducing tunnel enlargement, the length of the interference screw should be as fit as possible with tunnel length in terms of using soft grafts. II, Prospectively comparative

  1. Implementation of LRFD geotechnical design for deep foundations using Texas Cone Penetrometer (TCP) test.

    DOT National Transportation Integrated Search

    2015-09-01

    This study provides resistance factors (I) for design of deep foundations to implement Load and Resistance Factor Design (LRFD) for bridge foundations using Texas Cone Penetrometer (TCP) Test data. Initial efforts were made to determine resistance fa...

  2. Effects of DCPD Cement Chemistry on Degradation Properties and Cytocompatibility: Comparison of MCPM/β-TCP and MCPM/HA Formulations

    PubMed Central

    Alge, Daniel L.; Goebel, W. Scott; Chu, Tien-Min Gabriel

    2013-01-01

    Dicalcium phosphate dihydrate (DCPD) cements are attractive biomaterials for bone repair, and a number of different DCPD cement formulations have been proposed in the literature. In this study we have specifically compared monocalcium phosphate monohydrate (MCPM)/hydroxyapatite (HA) and MCPM/β-tricalcium phosphate (β-TCP) formulations to test the hypothesis that DCPD cement chemistry affects the degradation properties and cytocompatibility of the cement. Using simple in vitro models we found that MCPM/β-TCP formulations degraded primarily by DCPD dissolution, which was associated with a slight pH drop and relatively low mass loss. Cytocompatibility testing of cement conditioned culture media revealed no significant change in cell viability relative to the negative control for all of the MCPM/β-TCP formulations. In contrast, the MCPM/HA formulations were prone to undergo rapid conversion of DCPD to HA, resulting in a sharp pH drop and extensive mass loss. A stoichiometric excess of HA in the cement was found to accelerate the conversion process, and significant cytotoxicity was observed for the MCPM/HA formulations containing excess HA. Collectively, these results show that, although the product of the setting reaction is the same, DCPD cements produced with MCPM/HA and MCPM/β-TCP formulations differ significantly in their degradation properties and cytocompatibility. These differences may have important implications for the selection of a DCPD cement formulation for clinical application. PMID:23428798

  3. Enhancement of periodontal tissue regeneration by transplantation of osteoprotegerin-engineered periodontal ligament stem cells.

    PubMed

    Su, Fang; Liu, Shi-Sen; Ma, Jun-Li; Wang, Dong-Sheng; E, Ling-Ling; Liu, Hong-Chen

    2015-03-12

    The objective of the present study was to evaluate the capacity of a tissue-engineered complex of human osteoprotegerin (hOPG)-transfected periodontal ligament stem cells (PDLSCs) seeding on beta-tricalcium phosphate (β-TCP) to regenerate alveolar bone defects in New Zealand rabbits. PDLSCs were isolated from rabbit periodontal ligament tissues and expanded in vitro to enrich PDLSC numbers, and their proliferative activities and differentiation capability were evaluated under specific induction conditions. Lentiviral vector containing hOPG and enhanced green fluorescent protein (EGFP) was constructed by using Gateway technology and transfected into rabbit PDLSCs. The expression of hOPG was determined with quantitative real-time reverse transcription-polymerase chain reaction and Western blot. The PDLSCs with or without engineered hOPG were seeded on β-TCP scaffolds prior to transplantation. Morphological characterization of cells and materials was done by scanning electron microscope. Twenty rabbits with alveolar bone defects were randomly allocated into four groups and transplanted with β-TCP, PDLSCs/β-TCP, and hOPG-transfected PDLSCs/β-TCP or were left untreated as a control. Animals were sacrificed 12 weeks after operation for histological observation and histomorphometric analysis. PDLSCs expressed STRO-1 and vementin and favored osteogenesis and adipogenesis in conditioned media. Expressions of hOPG were significantly upregulated after transfection of the lentiviral vector into PDLSCs. PDLSCs attached and spread well on β-TCP, and there was no significant difference in growth of PDLSCs on β-TCP between the hOPG transfection group and the non-transfection group. The histological observation and histomorphometric analysis showed that the hOPG-transfected PDLSCs/β-TCP complex exhibited an earlier mineralization and more bone formation inside the scaffold than control, β-TCP, and PDLSCs/β-TCP complexes. Implantation of hOPG-transfected PDLSCs

  4. Prospective Randomized Controlled Trial of Hindfoot and Ankle Fusions Treated With rhPDGF-BB in Combination With a β-TCP-Collagen Matrix.

    PubMed

    Daniels, Timothy R; Younger, Alastair S E; Penner, Murray J; Wing, Kevin J; Le, Ian L D; Russell, Iain S; Lalonde, Karl-André; Evangelista, Peter T; Quiton, Jovelyn D; Glazebrook, Mark; DiGiovanni, Christopher W

    2015-07-01

    Ankle and hindfoot arthrodesis is often supplemented with autograft to promote bony union. Autograft harvest can lead to increased perioperative morbidity. Purified recombinant human platelet-derived growth factor BB homodimer (rhPDGF-BB) has stimulated bone formation in mandibular defects and hindfoot fusion. This randomized controlled trial evaluated the efficacy and safety of rhPDGF-BB combined with an injectable, osteoconductive beta-tricalcium phosphate (β-TCP)-collagen matrix versus autograft in ankle and hindfoot fusions. Seventy-five patients requiring ankle or hindfoot fusion were randomized 5:1 for rhPDGF-BB/β-TCP-collagen (treatment, n = 63) or autograft (control, n = 12). Prospective analysis included 142 autograft control subjects from another clinical trial with identical study protocols. Standardized operative and postoperative protocols were used. Patients underwent standard internal fixation augmented with autograft or 0.3 mg/mL rhPDGF-BB/β-TCP-collagen. Radiologic, clinical, and quality-of-life outcomes were assessed over 52 weeks. Primary outcome was joint fusion (50% or more osseous bridging on computed tomography) at 24 weeks. Secondary outcomes included radiographs, clinical healing status, visual analog scale pain score, American Orthopaedic Foot & Ankle Society Ankle-Hindfoot Scale score, Foot Function Index score, and Short Form-12 score. Noninferiority P values were calculated. Complete fusion of all involved joints at 24 weeks as indicated by computed tomography was achieved in 53 of 63 (84%) rhPDGF-BB/β-TCP-collagen-treated patients and 100 of 154 (65%) autograft-treated patients (P < .001). Mean time to fusion was 14.3 ± 8.9 weeks for rhPDGF-BB/β-TCP-collagen patients versus 19.7 ± 11.5 weeks for autograft patients (P < .01). Clinical success at 52 weeks was achieved in 57 of 63 (91%) rhPDGF-BB/β-TCP-collagen patients and 120 of 154 (78%) autograft patients (P < .001). Safety-related outcomes were equivalent. Autograft controls

  5. SU-E-J-30: Benchmark Image-Based TCP Calculation for Evaluation of PTV Margins for Lung SBRT Patients

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, M; Chetty, I; Zhong, H

    2014-06-01

    Purpose: Tumor control probability (TCP) calculated with accumulated radiation doses may help design appropriate treatment margins. Image registration errors, however, may compromise the calculated TCP. The purpose of this study is to develop benchmark CT images to quantify registration-induced errors in the accumulated doses and their corresponding TCP. Methods: 4DCT images were registered from end-inhale (EI) to end-exhale (EE) using a “demons” algorithm. The demons DVFs were corrected by an FEM model to get realistic deformation fields. The FEM DVFs were used to warp the EI images to create the FEM-simulated images. The two images combined with the FEM DVFmore » formed a benchmark model. Maximum intensity projection (MIP) images, created from the EI and simulated images, were used to develop IMRT plans. Two plans with 3 and 5 mm margins were developed for each patient. With these plans, radiation doses were recalculated on the simulated images and warped back to the EI images using the FEM DVFs to get the accumulated doses. The Elastix software was used to register the FEM-simulated images to the EI images. TCPs calculated with the Elastix-accumulated doses were compared with those generated by the FEM to get the TCP error of the Elastix registrations. Results: For six lung patients, the mean Elastix registration error ranged from 0.93 to 1.98 mm. Their relative dose errors in PTV were between 0.28% and 6.8% for 3mm margin plans, and between 0.29% and 6.3% for 5mm-margin plans. As the PTV margin reduced from 5 to 3 mm, the mean TCP error of the Elastix-reconstructed doses increased from 2.0% to 2.9%, and the mean NTCP errors decreased from 1.2% to 1.1%. Conclusion: Patient-specific benchmark images can be used to evaluate the impact of registration errors on the computed TCPs, and may help select appropriate PTV margins for lung SBRT patients.« less

  6. Genome-wide identification and characterization of TCP genes involved in ovule development of Phalaenopsis equestris

    PubMed Central

    Lin, Yu-Fu; Chen, You-Yi; Hsiao, Yu-Yun; Shen, Ching-Yu; Hsu, Jui-Ling; Yeh, Chuan-Ming; Mitsuda, Nobutaka; Ohme-Takagi, Masaru; Liu, Zhong-Jian; Tsai, Wen-Chieh

    2016-01-01

    TEOSINTE-BRANCHED/CYCLOIDEA/PCF (TCP) proteins are plant-specific transcription factors known to have a role in multiple aspects of plant growth and development at the cellular, organ and tissue levels. However, there has been no related study of TCPs in orchids. Here we identified 23 TCP genes from the genome sequence of Phalaenopsis equestris. Phylogenetic analysis distinguished two homology classes of PeTCP transcription factor families: classes I and II. Class II was further divided into two subclasses, CIN and CYC/TB1. Spatial and temporal expression analysis showed that PePCF10 was predominantly expressed in ovules at early developmental stages and PeCIN8 had high expression at late developmental stages in ovules, with overlapping expression at day 16 after pollination. Subcellular localization and protein–protein interaction analyses revealed that PePCF10 and PeCIN8 could form homodimers and localize in the nucleus. However, PePCF10 and PeCIN8 could not form heterodimers. In transgenic Arabidopsis thaliana plants (overexpression and SRDX, a super repression motif derived from the EAR-motif of the repression domain of tobacco ETHYLENE-RESPONSIVE ELEMENT-BINDING FACTOR 3 and SUPERMAN, dominantly repressed), the two genes helped regulate cell proliferation. Together, these results suggest that PePCF10 and PeCIN8 play important roles in orchid ovule development by modulating cell division. PMID:27543606

  7. In vitro biological evaluation of beta-TCP/HDPE--A novel orthopedic composite: a survey using human osteoblast and fibroblast bone cells.

    PubMed

    Homaeigohar, S Sh; Shokrgozar, M A; Khavandi, A; Sadi, A Yari

    2008-02-01

    Beta-tricalcium phosphate reinforced high density polyethylene (beta-TCP/HDPE) was prepared to simulate bone composition and to study its capacity to act as bone tissue. This material was produced by replacing the mineral component and collagen soft tissue of the bone with beta-TCP and HDPE, respectively. The biocompatibility of the composite samples with different volume fractions of TCP (20, 30 and 40 vol %) was examined in vitro using two osteoblast cell lines G-292 and Saos-2, and also a type of fibroblast cell isolated from bone tissue, namely human bone fibroblast (HBF) by proliferation, and cell adhesion assays. Cell-material interaction with the surface of the composite samples was examined by scanning electron microscopy (SEM). The effect of beta-TCP/HDPE on the behavior of osteoblast and fibroblast cells was compared with those of composite and negative control samples; polyethylene (PE) and tissue culture polystyrene (TPS), respectively. In general, the results showed that the composite samples containing beta-TCP as reinforcement supported a higher rate of proliferation by various bone cells after 3, 7, and 14 days of incubation compared to the composite control sample. Furthermore, more osteoblast cells were attached to the surface of the composite samples when compared to the composite control samples after the above incubation periods (p < 0.05), while in the case of HBF an equal or even higher number of cells adhered to PE was observed. The number of adhered osteoblast cells was almost equal and in some days even higher than the number of adhered cells on negative control sample, while in the case of fibroblast this difference was significantly higher than TPS (p < 0.05). Adhered cells presented a normal morphology by SEM and many of the cells were observed to be undergoing cell division. These findings indicate that beta-TCP/HDPE composites are biocompatible, nontoxic, and act to stimulate proliferation and adhesion of the cells, whether osteoblast

  8. The Live Attenuated Cholera Vaccine CVD 103-HgR Primes Responses to the Toxin-Coregulated Pilus Antigen TcpA in Subjects Challenged with Wild-Type Vibrio cholerae.

    PubMed

    Mayo-Smith, Leslie M; Simon, Jakub K; Chen, Wilbur H; Haney, Douglas; Lock, Michael; Lyon, Caroline E; Calderwood, Stephen B; Kirkpatrick, Beth D; Cohen, Mitchell; Levine, Myron M; Gurwith, Marc; Harris, Jason B

    2017-01-01

    One potential advantage of live attenuated bacterial vaccines is the ability to stimulate responses to antigens which are only expressed during the course of infection. To determine whether the live attenuated cholera vaccine CVD 103-HgR (Vaxchora) results in antibody responses to the in vivo-induced toxin-coregulated pilus antigen TcpA, we measured IgA and IgG responses to Vibrio cholerae O1 El Tor TcpA in a subset of participants in a recently reported experimental challenge study. Participants were challenged with V. cholerae O1 El Tor Inaba N16961 either 10 days or 90 days after receiving the vaccine or a placebo. Neither vaccination nor experimental infection with V. cholerae alone resulted in a robust TcpA IgG or IgA response, but each did elicit a strong response to cholera toxin. However, compared to placebo recipients, vaccinees had a marked increase in IgG TcpA antibodies following the 90-day challenge, suggesting that vaccination with CVD 103-HgR resulted in priming for a subsequent response to TcpA. No such difference between vaccine and placebo recipients was observed for volunteers challenged 10 days after vaccination, indicating that this was insufficient time for vaccine-induced priming of the TcpA response. The priming of the response to TcpA and potentially other antigens expressed in vivo by attenuated V. cholerae may have relevance to the maintenance of immunity in areas where cholera is endemic. Copyright © 2017 American Society for Microbiology.

  9. Optical Photometry of the Nova Outburst TCP J04432130+4721280 (V392 Per)

    NASA Astrophysics Data System (ADS)

    Konyves-Toth, R.; Csak, B.; Pal, A.; Vinko, J.

    2018-05-01

    We obtained new photometric observations of TCP J04432130+4721280 (V392 Per, ATel #11588, #11590), R.A = 04:43:21.38, Dec = +47:21:25.9, on 2018-04-30.80 UT. The data were taken with the 60/90 cm Schmidt telescope at Konkoly Observatory, Piszkesteto, Hungary.

  10. Computed 88% TCP dose for SBRT of NSCLC from tumour hypoxia modelling

    NASA Astrophysics Data System (ADS)

    Ruggieri, Ruggero; Stavreva, Nadejda; Naccarato, Stefania; Stavrev, Pavel

    2013-07-01

    In small NSCLC, 88% local control at three years from SBRT was reported both for schedule (20-22 Gy ×3) (Fakiris et al 2009 Int. J. Radiat. Oncol. Biol. Phys. 75 677-82), actually close to (18-20 Gy ×3) if density correction is properly applied, and for schedules (18 Gy ×3) and (11 Gy ×5) (Palma et al 2012 Int. J. Radiat. Oncol. Biol. Phys. 82 1149-56). Here, we compare our computed iso-TCP = 88% dose per fraction (d88) for three and five fractions (n) with such clinically adopted ones. Our TCP model accounts for tumour repopulation, at rate λ (d-1), reoxygenation of chronic hypoxia (ch-), at rate a (d-1) and fluctuating oxygenation of acute hypoxia (ah-), with hypoxic fraction (C) of the acutely hypoxic fractional volume (AHF). Out of the eight free parameters whose values we had fitted to in vivo animal data (Ruggieri et al 2012 Int. J. Radiat. Oncol. Biol. Phys. 83 1603-8), we here maintained (a(d-1), C, OERch, OERah/OERch, AHF, CHF) = (0.026, 0.17, 1.9, 2.2, 0.033, 0.145) while rescaling the initial total number of clonogens (No) according to the ratio of NSCLC on animal median tumour volumes. From the clinical literature, the usually assumed (αo/βo(Gy), λ(d-1)) = (10, 0.217) for the well-oxygenated (o-)cells were taken. By normal (lognormal) random sampling of all parameter values over their 95% C.I., the uncertainty on present d88(n) computations was estimated. Finally, SBRT intra-tumour dose heterogeneity was simulated by a 1.3 dose boost ratio on 50% of tumour volume. Computed d88(±1σ) were 19.0 (16.3; 21.7) Gy, for n = 3; 10.4 (8.7; 12.1) Gy, for n = 5; 5.8 (5.2; 6.4) Gy, for n = 8; 4.0 (3.6; 4.3) Gy, for n = 12. Furthermore, the iso-TCP = 88% total dose, D88(n) = d88(n)*n, exhibited a relative minimum around n = 8. Computed d88(n = 3, 5) are strictly consistent with the clinically adopted ones, which confirms the validity of LQ-model-based TCP predictions at the doses used in SBRT if a highly radioresistant cell subpopulation is properly

  11. Evidence of the direct involvement of the substrate TCP radical in functional switching from oxyferrous O2 carrier to ferric peroxidase in the dual-function hemoglobin/dehaloperoxidase from Amphitrite ornata.

    PubMed

    Sun, Shengfang; Sono, Masanori; Du, Jing; Dawson, John H

    2014-08-05

    The coelomic O2-binding hemoglobin dehaloperoxidase (DHP) from the sea worm Amphitrite ornata is a dual-function heme protein that also possesses a peroxidase activity. Two different starting oxidation states are required for reversible O2 binding (ferrous) and peroxidase (ferric) activity, bringing into question how DHP manages the two functions. In our previous study, the copresence of substrate 2,4,6-trichlorophenol (TCP) and H2O2 was found to be essential for the conversion of oxy-DHP to enzymatically active ferric DHP. On the basis of that study, a functional switching mechanism involving substrate radicals (TCP(•)) was proposed. To further support this mechanism, herein we report details of our investigations into the H2O2-mediated conversion of oxy-DHP to the ferric or ferryl ([TCP] < [H2O2]) state triggered by both biologically relevant [TCP and 4-bromophenol (4-BP)] and nonrelevant (ferrocyanide) compounds. At <50 μM H2O2, all of these conversion reactions are completely inhibited by ferric heme ligands (KCN and imidazole), indicating the involvement of ferric DHP. Furthermore, the spin-trapping reagent 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) effectively inhibits the TCP/4-BP (but not ferrocyanide)-triggered conversion of oxy-DHP to ferric DHP. These results and O2 concentration-dependent conversion rates observed in this study demonstrate that substrate TCP triggers the conversion of oxy-DHP to a peroxidase by TCP(•) oxidation of the deoxyferrous state. TCP(•) is progressively generated, by increasingly produced amounts of ferric DHP, upon H2O2 oxidation of TCP catalyzed initially by trace amounts of ferric enzyme present in the oxy-DHP sample. The data presented herein further address the mechanism of how the halophenolic substrate triggers the conversion of hemoglobin DHP into a peroxidase.

  12. Airpower In The Information Age: Embracing TCP/IP Within Airborne Networks

    DTIC Science & Technology

    2015-04-01

    proved successful at seamlessly connecting large numbers of users to a vast array of applications. Airborne TCP/IP communication systems within DoD are...behind the development of next generation weapons systems. Admiral Fitzgerald recommends that the network architecture be developed and the...environment makes traditional ISR much more difficult and the military will need to rely on fifth- generation platforms like the F-35 that are able to

  13. Effect of Co on Discontinuous Precipitation Transformation with TCP Phase in Ni-based Alloy Containing Re

    NASA Astrophysics Data System (ADS)

    Shi, Qianying; An, Ning; Huo, Jiajie; Zheng, Yunrong; Feng, Qiang

    2017-05-01

    The effect of Co on discontinuous precipitation (DP) transformation involving the formation of topologically close-packed (TCP) phase was investigated in three Ni-Cr-Re model alloys containing different levels of Co. One typical TCP phase, σ, was generated within DP cellular colonies along the migrating grain boundaries in experimental alloys during aging treatment. As a result of the increased solubility of Re in the γ matrix and enlarged interlamellar spacing of σ precipitates inside of growing DP colonies, Co addition suppressed the formation of σ phase and associated DP colonies. This study suggests that Co could potentially serve as a microstructural stabilizer in Re-containing Ni-base superalloys, which provides an alternative method for the composition optimization of superalloys.

  14. Evaluation of Swift Start TCP in Long-Delay Environment

    NASA Technical Reports Server (NTRS)

    Lawas-Grodek, Frances J.; Tran, Diepchi T.

    2004-01-01

    This report presents the test results of the Swift Start algorithm in single-flow and multiple-flow testbeds under the effects of high propagation delays, various slow bottlenecks, and small queue sizes. Although this algorithm estimates capacity and implements packet pacing, the findings were that in a heavily congested link, the Swift Start algorithm will not be applicable. The reason is that the bottleneck estimation is falsely influenced by timeouts induced by retransmissions and the expiration of delayed acknowledgment (ACK) timers, thus causing the modified Swift Start code to fall back to regular transmission control protocol (TCP).

  15. Genome-wide identification and characterization of TCP genes involved in ovule development of Phalaenopsis equestris.

    PubMed

    Lin, Yu-Fu; Chen, You-Yi; Hsiao, Yu-Yun; Shen, Ching-Yu; Hsu, Jui-Ling; Yeh, Chuan-Ming; Mitsuda, Nobutaka; Ohme-Takagi, Masaru; Liu, Zhong-Jian; Tsai, Wen-Chieh

    2016-09-01

    TEOSINTE-BRANCHED/CYCLOIDEA/PCF (TCP) proteins are plant-specific transcription factors known to have a role in multiple aspects of plant growth and development at the cellular, organ and tissue levels. However, there has been no related study of TCPs in orchids. Here we identified 23 TCP genes from the genome sequence of Phalaenopsis equestris Phylogenetic analysis distinguished two homology classes of PeTCP transcription factor families: classes I and II. Class II was further divided into two subclasses, CIN and CYC/TB1. Spatial and temporal expression analysis showed that PePCF10 was predominantly expressed in ovules at early developmental stages and PeCIN8 had high expression at late developmental stages in ovules, with overlapping expression at day 16 after pollination. Subcellular localization and protein-protein interaction analyses revealed that PePCF10 and PeCIN8 could form homodimers and localize in the nucleus. However, PePCF10 and PeCIN8 could not form heterodimers. In transgenic Arabidopsis thaliana plants (overexpression and SRDX, a super repression motif derived from the EAR-motif of the repression domain of tobacco ETHYLENE-RESPONSIVE ELEMENT-BINDING FACTOR 3 and SUPERMAN, dominantly repressed), the two genes helped regulate cell proliferation. Together, these results suggest that PePCF10 and PeCIN8 play important roles in orchid ovule development by modulating cell division. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  16. Spectroscopic classification of TCP J00333837+4836022 as a nova in NGC 147

    NASA Astrophysics Data System (ADS)

    Williams, S. C.; Darnley, M. J.

    2017-12-01

    We obtained a spectrum of the transient TCP J00333837+4836022 (see CBAT TOCP) with the SPRAT spectrograph (resolution R 350; Piascik et al. 2014) on the 2-m Liverpool Telescope (Steele et al. 2004) on 2017 Dec 24.82 UT. The only emission clearly present is H & alpha;, which displays a P-Cygni profile.

  17. Approaches in highly parameterized inversion - GENIE, a general model-independent TCP/IP run manager

    USGS Publications Warehouse

    Muffels, Christopher T.; Schreuder, Willem A.; Doherty, John E.; Karanovic, Marinko; Tonkin, Matthew J.; Hunt, Randall J.; Welter, David E.

    2012-01-01

    GENIE is a model-independent suite of programs that can be used to generally distribute, manage, and execute multiple model runs via the TCP/IP infrastructure. The suite consists of a file distribution interface, a run manage, a run executer, and a routine that can be compiled as part of a program and used to exchange model runs with the run manager. Because communication is via a standard protocol (TCP/IP), any computer connected to the Internet can serve in any of the capacities offered by this suite. Model independence is consistent with the existing template and instruction file protocols of the widely used PEST parameter estimation program. This report describes (1) the problem addressed; (2) the approach used by GENIE to queue, distribute, and retrieve model runs; and (3) user instructions, classes, and functions developed. It also includes (4) an example to illustrate the linking of GENIE with Parallel PEST using the interface routine.

  18. The diagnostic performance of recombinant Trypanosoma cruzi ribosomal P2beta protein is influenced by its expression system.

    PubMed

    Marcipar, Iván S; Olivares, María Laura; Robles, Lucía; Dekanty, Andrés; Marcipar, Alberto; Silber, Ariel M

    2004-03-01

    In the present work, we have determined the effect of expression vectors and their corresponding host bacteria on the antigenic performance of Trypanosoma cruzi P2beta (TcP2beta) full-length recombinant protein. The gene encoding the TcP2beta ribosomal protein was cloned in pMAL-c2 and pET-32a vectors that allow the expression of high levels of soluble fusion proteins. A panel of 32 positive and 32 negative sera was assayed with the purified proteins expressed using pMal-c2 (TcP2beta-MBP) and pET-32a (TcP2beta-TRX) vectors and with MBP and TRX purified from pMAL-c2 and pET-32a vectors, respectively. The antigenic behavior of each TcP2beta recombinant protein differed in the diagnostic performance in terms of DI(+) (93.7 for TcP2beta-MBP vs 100% for TcP2beta-TRX), in DI(-) (90.5 for TcP2beta-MBP vs 100% for TcP2beta-TRX) and in cross-reaction with negative sera. To determine if the higher reactivity of expressed pMAL-c2 protein was due to folding during protein expression or to a steric effect related to the protein adsorption at the titration plate, the reactivity of sera against soluble proteins was assessed by ELISA inhibition assays. As each soluble protein preserved its level of reactivity, we concluded that differences in reactivity were due to intrinsic characteristics of the proteins and not to differences in patterns of adsorption to the plates.

  19. Enhancing End-to-End Performance of Information Services Over Ka-Band Global Satellite Networks

    NASA Technical Reports Server (NTRS)

    Bhasin, Kul B.; Glover, Daniel R.; Ivancic, William D.; vonDeak, Thomas C.

    1997-01-01

    The Internet has been growing at a rapid rate as the key medium to provide information services such as e-mail, WWW and multimedia etc., however its global reach is limited. Ka-band communication satellite networks are being developed to increase the accessibility of information services via the Internet at global scale. There is need to assess satellite networks in their ability to provide these services and interconnect seamlessly with existing and proposed terrestrial telecommunication networks. In this paper the significant issues and requirements in providing end-to-end high performance for the delivery of information services over satellite networks based on various layers in the OSI reference model are identified. Key experiments have been performed to evaluate the performance of digital video and Internet over satellite-like testbeds. The results of the early developments in ATM and TCP protocols over satellite networks are summarized.

  20. Perform or Else: The Performative Enhancement of Teacher Professionalism

    ERIC Educational Resources Information Center

    Liew, Warren Mark

    2012-01-01

    The Singapore Ministry of Education's Enhanced Performance Management System (EPMS) was instituted in 2005 as a system of professional accountability to enhance the standards and stakes of teacher professionalism in schools. This essay explores how the EPMS, with its underlying paradigm of performance management, functions as a "technology of…

  1. Radiobiological Impact of Reduced Margins and Treatment Technique for Prostate Cancer in Terms of Tumor Control Probability (TCP) and Normal Tissue Complication Probability (NTCP)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jensen, Ingelise, E-mail: inje@rn.d; Carl, Jesper; Lund, Bente

    2011-07-01

    Dose escalation in prostate radiotherapy is limited by normal tissue toxicities. The aim of this study was to assess the impact of margin size on tumor control and side effects for intensity-modulated radiation therapy (IMRT) and 3D conformal radiotherapy (3DCRT) treatment plans with increased dose. Eighteen patients with localized prostate cancer were enrolled. 3DCRT and IMRT plans were compared for a variety of margin sizes. A marker detectable on daily portal images was presupposed for narrow margins. Prescribed dose was 82 Gy within 41 fractions to the prostate clinical target volume (CTV). Tumor control probability (TCP) calculations based on themore » Poisson model including the linear quadratic approach were performed. Normal tissue complication probability (NTCP) was calculated for bladder, rectum and femoral heads according to the Lyman-Kutcher-Burman method. All plan types presented essentially identical TCP values and very low NTCP for bladder and femoral heads. Mean doses for these critical structures reached a minimum for IMRT with reduced margins. Two endpoints for rectal complications were analyzed. A marked decrease in NTCP for IMRT plans with narrow margins was seen for mild RTOG grade 2/3 as well as for proctitis/necrosis/stenosis/fistula, for which NTCP <7% was obtained. For equivalent TCP values, sparing of normal tissue was demonstrated with the narrow margin approach. The effect was more pronounced for IMRT than 3DCRT, with respect to NTCP for mild, as well as severe, rectal complications.« less

  2. The small phytoplasma virulence effector SAP11 contains distinct domains required for nuclear targeting and CIN-TCP binding and destabilization.

    PubMed

    Sugio, Akiko; MacLean, Allyson M; Hogenhout, Saskia A

    2014-05-01

    Phytoplasmas are insect-transmitted bacterial phytopathogens that secrete virulence effectors and induce changes in the architecture and defense response of their plant hosts. We previously demonstrated that the small (± 10 kDa) virulence effector SAP11 of Aster Yellows phytoplasma strain Witches' Broom (AY-WB) binds and destabilizes Arabidopsis CIN (CINCINNATA) TCP (TEOSINTE-BRANCHED, CYCLOIDEA, PROLIFERATION FACTOR 1 AND 2) transcription factors, resulting in dramatic changes in leaf morphogenesis and increased susceptibility to phytoplasma insect vectors. SAP11 contains a bipartite nuclear localization signal (NLS) that targets this effector to plant cell nuclei. To further understand how SAP11 functions, we assessed the involvement of SAP11 regions in TCP binding and destabilization using a series of mutants. SAP11 mutants lacking the entire N-terminal domain, including the NLS, interacted with TCPs but did not destabilize them. SAP11 mutants lacking the C-terminal domain were impaired in both binding and destabilization of TCPs. These SAP11 mutants did not alter leaf morphogenesis. A SAP11 mutant that did not accumulate in plant nuclei (SAP11ΔNLS-NES) was able to bind and destabilize TCP transcription factors, but instigated weaker changes in leaf morphogenesis than wild-type SAP11. Overall the results suggest that phytoplasma effector SAP11 has a modular organization in which at least three domains are required for efficient CIN-TCP destabilization in plants. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  3. Specific surface area effect on adsorption of chlorpyrifos and TCP by soils and modeling

    USDA-ARS?s Scientific Manuscript database

    The adsorption of chlorpyrifos and TCP (3,5,6, trichloro-2-pyridinol) was determined in four soils (Mollisol, Inceptisol, Entisol, Alfisol) having different specific surface areas (19–84 m2/g) but rather similar organic matter content (2.4–3.5%). Adsorption isotherms were derived from batch equilibr...

  4. Integration in PACS of DICOM with TCP/IP, SQL, and X Windows

    NASA Astrophysics Data System (ADS)

    Reijns, Gerard L.

    1994-05-01

    The DICOM standard (Digital Imaging and Communications in Medicine) has been developed in order to obtain compatibility at the higher OSI levels. This paper describes the implementation of DICOM into our developed low cost PACS, which uses as much as possible standard software and standard protocols such as SQL, X Windows and TCP/IP. We adopted the requirement that all messages on the communication network have to be DICOM compatible. The translation between DICOM messages and SQL commands, which drive the relational data base, has been accommodated in our PACS supervisor. The translation takes only between 10 and 20 milliseconds. Images, that will be used the current day are stored in a distributed, parallel operating image base for reasons of performance. Extensive use has been made of X Windows to visualize images. A maximum of 12 images can simultaneously be displayed, of which one selected image can be manipulated (e.g., magnified, rotated, etc.), without affecting the other displayed images. The emphasis of the future work will be on performance measurements and modeling of our PACS and bringing the results of both methods in agreement with each other.

  5. Bone Regeneration Using a Mixture of Silicon-Substituted Coral HA and β-TCP in a Rat Calvarial Bone Defect Model

    PubMed Central

    Roh, Jiyeon; Kim, Ji-Youn; Choi, Young-Muk; Ha, Seong-Min; Kim, Kyoung-Nam; Kim, Kwang-Mahn

    2016-01-01

    The demand of bone graft materials has been increasing. Among various origins of bone graft materials, natural coral composed of up to 99% calcium carbonate was chosen and converted into hydroxyapatite (HA); silicon was then substituted into the HA. Then, the Si-HA was mixed with β-tricalcium phosphate (TCP) in the ratios 100:0 (S100T0), 70:30 (S70T30), 60:40 (S60T40), and 50:50 (S50T50). The materials were implanted for four and eight weeks in a rat calvarial bone defect model (8 mm). The MBCPTM (HA:β-TCP = 60:40, Biomatalante, Vigneux de Bretagne, France) was used as a control. After euthanasia, the bone tissue was analyzed by making histological slides. From the results, S60T40 showed the fastest bone regeneration in four weeks (p < 0.05). In addition, S60T40, S50T50, and MBCPTM showed significant new bone formation in eight weeks (p < 0.05). In conclusion, Si-HA/TCP showed potential as a bone graft material. PMID:28787903

  6. Bone Regeneration Using a Mixture of Silicon-Substituted Coral HA and β-TCP in a Rat Calvarial Bone Defect Model.

    PubMed

    Roh, Jiyeon; Kim, Ji-Youn; Choi, Young-Muk; Ha, Seong-Min; Kim, Kyoung-Nam; Kim, Kwang-Mahn

    2016-02-06

    The demand of bone graft materials has been increasing. Among various origins of bone graft materials, natural coral composed of up to 99% calcium carbonate was chosen and converted into hydroxyapatite (HA); silicon was then substituted into the HA. Then, the Si-HA was mixed with β-tricalcium phosphate (TCP) in the ratios 100:0 (S100T0), 70:30 (S70T30), 60:40 (S60T40), and 50:50 (S50T50). The materials were implanted for four and eight weeks in a rat calvarial bone defect model (8 mm). The MBCPTM (HA:β-TCP = 60:40, Biomatalante, Vigneux de Bretagne, France) was used as a control. After euthanasia, the bone tissue was analyzed by making histological slides. From the results, S60T40 showed the fastest bone regeneration in four weeks (p < 0.05). In addition, S60T40, S50T50, and MBCPTM showed significant new bone formation in eight weeks (p < 0.05). In conclusion, Si-HA/TCP showed potential as a bone graft material.

  7. Assessment of bone repair in critical-size defect in the calvarium of rats after the implantation of tricalcium phosphate beta (β-TCP).

    PubMed

    de Freitas Silva, Leonardo; de Carvalho Reis, Erik Neiva Ribeiro; Barbara, Tânia Aparecida; Bonardi, João Paulo; Garcia, Idelmo Rangel; de Carvalho, Paulo Sérgio Perri; Ponzoni, Daniela

    2017-07-01

    Evaluating the osteoconductive property of tricalcium phosphate beta (β-TCP) in comparison to that of inorganic bovine bone for repair in a critical-size defect in the rat calvarium. Critical-size defects of 7mm were made with a trephine in the calvaria of 48 Wistar rats. The animals were divided into four groups, and the defects in each group were filled with tricalcium phosphate beta (β-TCP), inorganic bovine bone (Bio-Oss), autogenous bone, or left empty. The animals were euthanized at two different time points (30 and 60days post-operation). All defects were recovered with a absorbable membrane of bovine cortical bone. Histological, histometric, and immunohistochemical (osteocalcin) assessments were carried out at 30 and 60days post-operation. At 30days post-operation, all groups showed areas of bone formation, predominantly when autogenous grafts were used. However, there were no statistically significant differences between the treatment groups (p>0.05). After 60days, there were similarities in the bone formation patterns between the β-TCP (26.32±) and Bio-Oss (17.35±) groups (p=0.549). In terms of the immunohistochemical assessment of osteocalcin, the clot group showed light to moderate staining at 30 and 60days. The autogenous group showed moderate staining at 30days and moderate to intense staining after 60days. The Bio-Oss group showed light to moderate staining after 30days and intense staining at 60days. The β-TCP group showed moderate staining at 30 and 60days post-operation. β-TCP is a good osteoconductive material with similar effects to those of inorganic bovine bone graft and is suitable for utilization in the repair of bone defects. Copyright © 2017 Elsevier GmbH. All rights reserved.

  8. Modeling of twisted and coiled polymer (TCP) muscle based on phenomenological approach

    NASA Astrophysics Data System (ADS)

    Karami, Farzad; Tadesse, Yonas

    2017-12-01

    Twisted and coiled polymers (TCP) muscles are linear actuators that respond to change in temperature. Exploiting high negative coefficient of thermal expansion (CTE) and helical geometry give them a significant ability to change length in a limited temperature range. Several applications and experimental data of these materials have been demonstrated in the last few years. To use these actuators in robotics and control system applications, a mathematical model for predicting their behavior is essential. In this work, a practical and accurate phenomenological model for estimating the displacement of TCP muscles, as a function of the load as well as input electrical current, is proposed. The problem is broken down into two parts, i.e. modeling of the electro-thermal and then the thermo-elastic behavior of the muscles. For the first part, a differential equation, with changing electrical resistance term, is derived. Next, by using a temperature-dependent modulus of elasticity and CTE as well as taking the geometry of the muscles into account, an expression for displacement is derived. Experimental data for different loads and actuation current levels are used for verifying the model and investigating its accuracy. The result shows a good agreement between the simulation and experimental results for all loads.

  9. Performance-Enhancing Drugs: Know the Risks

    MedlinePlus

    ... edge by taking muscle-building supplements or other performance-enhancing drugs? Learn how these drugs work and how they can affect your health. By Mayo Clinic Staff Most serious athletes will tell you that the ... performance-enhancing drugs has become increasingly common. But using ...

  10. Aeronautical Related Applications Using ATN and TCP/IP Research Report

    NASA Technical Reports Server (NTRS)

    Dhas, C.; Mulkerin, T.; Wargo, C.; Nielsen, R.; Gaughan, T.; Griner, James H., Jr. (Technical Monitor)

    2000-01-01

    The course for the future aeronautical communications architecture has been defined for more than 10 years and is known as the Aeronautical Telecommunication Network (ATN). However, the operational implementations of making use of the ATN remain 3-5 years away, and these implementations are still only in the early phases of long-range projects. Thus, it is an objective of this effort to consider what the potential outcome within the air transport industry may be, given the rapid growth in commercial-off-the-shelf (COTS) products, networks, and services that are based upon the Internet TCP/IP protocol suite.

  11. Radiobiological impact of reduced margins and treatment technique for prostate cancer in terms of tumor control probability (TCP) and normal tissue complication probability (NTCP).

    PubMed

    Jensen, Ingelise; Carl, Jesper; Lund, Bente; Larsen, Erik H; Nielsen, Jane

    2011-01-01

    Dose escalation in prostate radiotherapy is limited by normal tissue toxicities. The aim of this study was to assess the impact of margin size on tumor control and side effects for intensity-modulated radiation therapy (IMRT) and 3D conformal radiotherapy (3DCRT) treatment plans with increased dose. Eighteen patients with localized prostate cancer were enrolled. 3DCRT and IMRT plans were compared for a variety of margin sizes. A marker detectable on daily portal images was presupposed for narrow margins. Prescribed dose was 82 Gy within 41 fractions to the prostate clinical target volume (CTV). Tumor control probability (TCP) calculations based on the Poisson model including the linear quadratic approach were performed. Normal tissue complication probability (NTCP) was calculated for bladder, rectum and femoral heads according to the Lyman-Kutcher-Burman method. All plan types presented essentially identical TCP values and very low NTCP for bladder and femoral heads. Mean doses for these critical structures reached a minimum for IMRT with reduced margins. Two endpoints for rectal complications were analyzed. A marked decrease in NTCP for IMRT plans with narrow margins was seen for mild RTOG grade 2/3 as well as for proctitis/necrosis/stenosis/fistula, for which NTCP <7% was obtained. For equivalent TCP values, sparing of normal tissue was demonstrated with the narrow margin approach. The effect was more pronounced for IMRT than 3DCRT, with respect to NTCP for mild, as well as severe, rectal complications. Copyright © 2011 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

  12. Follow-up Photometry of the Microlensing Event TCP J05074264+2447555

    NASA Astrophysics Data System (ADS)

    Konyves-Toth, R.; Pal, A.; Ordasi, A.; Vinko, J.

    2017-11-01

    We report photometric observations of TCP J05074264+2447555 (R.A. = 05:08:43, Dec=+24:47:56), a proposed microlensing event at peak magnitude of V 11.5, discovered by T.Kojima UT 2017-10-25.688, and later confirmed by ASAS-SN (ATel #10923) Our data were taken with the 60/90 cm Schmidt telescope and the 1-meter RCC Telescope through Bessell B,V,R,I filters at Konkoly Observatory, Piszkesteto, Hungary between UT 2017-11-03.9 and 2017-11-04.9.

  13. Bone formation in vivo induced by Cbfa1-carrying adenoviral vectors released from a biodegradable porous β-tricalcium phosphate (β-TCP) material.

    PubMed

    Uemura, Toshimasa; Kojima, Hiroko

    2011-06-01

    Overexpression of Cbfa1 (a transcription factor indispensable for osteoblastic differentiation) is expected to induce the formation of bone directly and indirectly in vivo by accelerating osteoblastic differentiation. Adenoviral vectors carrying the cDNA of Cbfa1/til-1(Adv-Cbf1) were allowed to be adsorbed onto porous blocks of β-tricalcium phosphate (β-TCP), a biodegradable ceramic, which were then implanted subcutaneously and orthotopically into bone defects. The adenoviral vectors were released sustainingly by biodegradation, providing long-term expression of the genes. Results of the subcutaneous implantation of Adv-Cbfa1-adsorbed β-TCP/osteoprogenitor cells suggest that a larger amount of bone formed in the pores of the implant than in the control material. Regarding orthotopic implantation into bone defects, the released Adv-Cbfa1 accelerated regeneration in the cortical bone, whereas it induced bone resorption in the marrow cavity. A safer gene transfer using a smaller amount of the vector was achieved using biodegradable porous β-TCP as a carrier.

  14. Bone formation in vivo induced by Cbfa1-carrying adenoviral vectors released from a biodegradable porous β-tricalcium phosphate (β-TCP) material

    NASA Astrophysics Data System (ADS)

    Uemura, Toshimasa; Kojima, Hiroko

    2011-06-01

    Overexpression of Cbfa1 (a transcription factor indispensable for osteoblastic differentiation) is expected to induce the formation of bone directly and indirectly in vivo by accelerating osteoblastic differentiation. Adenoviral vectors carrying the cDNA of Cbfa1/til-1(Adv-Cbf1) were allowed to be adsorbed onto porous blocks of β-tricalcium phosphate (β-TCP), a biodegradable ceramic, which were then implanted subcutaneously and orthotopically into bone defects. The adenoviral vectors were released sustainingly by biodegradation, providing long-term expression of the genes. Results of the subcutaneous implantation of Adv-Cbfa1-adsorbed β-TCP/osteoprogenitor cells suggest that a larger amount of bone formed in the pores of the implant than in the control material. Regarding orthotopic implantation into bone defects, the released Adv-Cbfa1 accelerated regeneration in the cortical bone, whereas it induced bone resorption in the marrow cavity. A safer gene transfer using a smaller amount of the vector was achieved using biodegradable porous β-TCP as a carrier.

  15. Bright gamma-ray emission from TCP J04432130+4721280 (V392 Per) detected by Fermi-LAT

    NASA Astrophysics Data System (ADS)

    Li, Kwan-Lok; Chomiuk, Laura; Strader, Jay

    2018-05-01

    We report the Fermi-LAT detection of the optical transient TCP J04432130+4721280 (V392 Per), which was discovered by Yuji Nakamura on 2018-04-29.4740 (CBET #4515) and later identified as a Galactic nova by Wagner et al. (ATel #11588).

  16. Creation of bony microenvironment with CaP and cell-derived ECM to enhance human bone-marrow MSC behavior and delivery of BMP-2

    PubMed Central

    Kang, Yunqing; Kim, Sungwoo; Khademhosseini, Ali; Yang, Yunzhi

    2011-01-01

    Extracellular matrix (ECM) comprises a rich meshwork of proteins and proteoglycans, which not only contains biological cues for cell behavior, but is also a reservoir for binding growth factors and controlling their release. Here we aimed to create a suitable bony microenvironment with cell-derived ECM and biodegradable β-tricalcium phosphate (β-TCP). More specifically, we investigated whether the ECM produced by bone marrow-derived mesenchymal stem cells (hBMSC) on a β-TCP scaffold can bind bone morphogenetic protein-2 (BMP-2) and control its release in a sustained manner, and further examined the effect of ECM and the BMP-2 released from ECM on cell behaviors. The ECM was obtained through culturing the hBMSC on a β-TCP porous scaffold and performing decellularization and sterilization. SEM, XPS, FTIR, and immunofluorescent staining results indicated the presence of ECM on the β-TCP and the amount of ECM increased with the incubation time. BMP-2 was loaded onto the β-TCP with and without ECM by immersing the scaffolds in the BMP-2 solution. The loading and release kinetics of the BMP-2 on the β-TCP/ECM were significantly slower than those on the β-TCP. The β-TCP/ECM exhibited a sustained release profile of the BMP-2, which was also affected by the amount of ECM. This is probably because the β-TCP/ECM has different binding mechanisms with BMP-2. The β-TCP/ECM promoted cell proliferation. Furthermore, the BMP-2-loaded β-TCP/ECM stimulated reorganization of the actin cytoskeleton, increased expression of alkaline phosphatase and calcium deposition by the cells compared to those without BMP-2 loading and the β-TCP with BMP-2 loading. PMID:21632105

  17. The Association between State Value-added Taxes and Tobacco Use in India- Evidence from GATS and TCP India Survey.

    PubMed

    Shang, Ce; Chaloupka, Frank J; Fong, Geoffrey T; Gupta, Prakash C; Pednekar, Mangesh S

    2017-08-30

    State value-added taxes (VAT) on tobacco products have been increased significantly in recent years in India. Evidence on how these VATs were associated with smoking is highly needed. State bidi and cigarette VAT rates were linked to Global Adult Tobacco Survey (GATS) India 2009-2010 and Tobacco Control Policy (TCP) India Survey waves 1 (2010-2011) and 2 (2012-2013), respectively. These linked data were used to analyze the associations between bidi VAT rates and bidi smoking, between cigarette VAT rates and cigarette smoking, and between the two VAT rates and dual use of bidis and cigarettes. Weighted logistic regressions were employed to examine GATS cross-sectional data, whereas Generalized Estimating Equations (GEE) were employed to examine longitudinal TCP data. We further stratified the analyses by gender. A 10% increase in cigarette VAT rates was associated with a 6.5% (p<0.001) decrease in dual use of cigarettes and bidis among adults and a 0.9% decrease (p<0.05) in cigarette smoking among males in TCP; and with a 21.6% decrease (p<0.05) in dual use among adults and a 17.2% decrease (p<0.001) in cigarette smoking among males in GATS. TCP analyses controlling for state fixed effects are less likely to be biased and indicate a cigarette price elasticity of - 0.44. As female smoking prevalence was extremely low, these associations were non-significant for females. Higher state cigarette VAT rates in India were significantly associated with lower cigarette smoking and lower dual use of cigarettes and bidis. Increasing state VAT rates may significantly reduce smoking in India. © The Author 2017. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Enhancing Workgroup Performance.

    ERIC Educational Resources Information Center

    1998

    This document contains four papers from a symposium on enhancing workgroup performance in human resource development (HRD). "Formation of Cross-Cultural Global Teams: Making Informed Choices on Team Composition" (Robert L. Dilworth) describes how a mixed class of U.S. and international students identified their cultural and learning…

  19. Sleep Deprivation Impairs and Caffeine Enhances My Performance, but Not Always Our Performance.

    PubMed

    Faber, Nadira S; Häusser, Jan A; Kerr, Norbert L

    2017-02-01

    What effects do factors that impair or enhance performance in individuals have when these individuals act in groups? We provide a framework, called the GIE ("Effects of Grouping on Impairments and Enhancements") framework, for investigating this question. As prominent examples for individual-level impairments and enhancements, we discuss sleep deprivation and caffeine. Based on previous research, we derive hypotheses on how they influence performance in groups, specifically process gains and losses in motivation, individual capability, and coordination. We conclude that the effect an impairment or enhancement has on individual-level performance is not necessarily mirrored in group performance: grouping can help or hurt. We provide recommendations on how to estimate empirically the effects individual-level performance impairments and enhancements have in groups. By comparing sleep deprivation to stress and caffeine to pharmacological cognitive enhancement, we illustrate that we cannot readily generalize from group results on one impairment or enhancement to another, even if they have similar effects on individual-level performance.

  20. Bioremediation of soils co-contaminated with heavy metals and 2,4,5-trichlorophenol by fruiting body of Clitocybe maxima.

    PubMed

    Liu, Hongying; Guo, Shanshan; Jiao, Kai; Hou, Junjun; Xie, Han; Xu, Heng

    2015-08-30

    Pot experiments were performed to investigate the single effect of 2,4,5-trichlorophenol (TCP) or heavy metals (Cu, Cd, Cu+Cd) and the combined effects of metals-TCP on the growth of Clitocybe maxima together with the accumulation of heavy metals as well as dissipation of TCP. Results showed a negative effect of contaminations on fruiting time and biomass of the mushroom. TCP decreased significantly in soils accounting for 70.66-96.24% of the initial extractable concentration in planted soil and 66.47-91.42% in unplanted soil, which showed that the dissipation of TCP was enhanced with mushroom planting. Higher biological activities (bacterial counts, soil respiration and laccase activity) were detected in planted soils relative to unplanted controls, and the enhanced dissipation of TCP in planted soils might be derived from the increased biological activities. The metals accumulation in mushroom increased with the augment of metal load, and the proportion of acetic acid (HOAc) extractable metal in soils with C. maxima was larger than that in unplanted soils, which may be an explanation of metal uptake by C. maxima. These results suggested that the presence of C. maxima was effective in promoting the bioremediation of soil contaminated with heavy metals and TCP. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Performance-enhancing drug use in young athletes.

    PubMed

    Laos, Carla; Metzl, Jordan D

    2006-10-01

    This article explores the issue of performance-enhancing drug use in adolescent athletes. The article describes current substances that are being used by adolescent athletes, explains their positive and negative effects, examines factors contributing to their increased use in adolescent athletes, and discusses approaches to educating adolescents about alternate means of enhancing their athletic performance. It is hoped that this information will be useful toward encouraging young athletes to pursue, safe, healthy, and natural means of performance enhancement, such as practice and strength training, to improve sports performance in a safe, effective manner.

  2. Sci—Fri PM: Topics — 04: What if bystander effects influence cell kill within a target volume? Potential consequences of dose heterogeneity on TCP and EUD on intermediate risk prostate patients

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Balderson, M.J.; Kirkby, C.; Department of Medical Physics, Tom Baker Cancer Centre, Calgary, Alberta

    In vitro evidence has suggested that radiation induced bystander effects may enhance non-local cell killing which may influence radiotherapy treatment planning paradigms. This work applies a bystander effect model, which has been derived from published in vitro data, to calculate equivalent uniform dose (EUD) and tumour control probability (TCP) and compare them with predictions from standard linear quadratic (LQ) models that assume a response due only to local absorbed dose. Comparisons between the models were made under increasing dose heterogeneity scenarios. Dose throughout the CTV was modeled with normal distributions, where the degree of heterogeneity was then dictated by changingmore » the standard deviation (SD). The broad assumptions applied in the bystander effect model are intended to place an upper limit on the extent of the results in a clinical context. The bystander model suggests a moderate degree of dose heterogeneity yields as good or better outcome compared to a uniform dose in terms of EUD and TCP. Intermediate risk prostate prescriptions of 78 Gy over 39 fractions had maximum EUD and TCP values at SD of around 5Gy. The plots only dropped below the uniform dose values for SD ∼ 10 Gy, almost 13% of the prescribed dose. The bystander model demonstrates the potential to deviate from the common local LQ model predictions as dose heterogeneity through a prostate CTV is varies. The results suggest the potential for allowing some degree of dose heterogeneity within a CTV, although further investigations of the assumptions of the bystander model are warranted.« less

  3. Sports medicine: performance-enhancing drugs.

    PubMed

    Gregory, Andrew J M; Fitch, Robert W

    2007-08-01

    Performance-enhancing drugs, ergogenic aids, or sports supplements have been a part of sports since sporting competition began and likely always will be. Considered cheating by purists and necessary by some athletes, we must accept the fact that they are used, understand why they are used, and study how to prevent their use to institute change. This article summarizes current information regarding the use of performance-enhancing drugs in young athletes and provides proven prevention strategies for instituting a program in your local schools.

  4. A new iron calcium phosphate material to improve the osteoconductive properties of a biodegradable ceramic: a study in rabbit calvaria.

    PubMed

    Manchón, Angel; Hamdan Alkhraisat, Mohammad; Rueda-Rodriguez, Carmen; Prados-Frutos, Juan Carlos; Torres, Jesús; Lucas-Aparicio, Julia; Ewald, Andrea; Gbureck, Uwe; López-Cabarcos, Enrique

    2015-10-20

    β-tricalcium phosphate (β-TCP) is an osteoconductive and biodegradable material used in bone regeneration procedures, while iron has been suggested as a tool to improve the biological performance of calcium phosphate-based materials. However, the mechanisms of interaction between these materials and human cells are not fully understood. In order to clarify this relationship, we have studied the iron role in β-TCP ceramics. Iron-containing β-TCPs were prepared by replacing CaCO3 with C6H5FeO7 at different molar ratios. X-ray diffraction analysis indicated the occurrence of β-TCP as the sole phase in the pure β-TCP and iron-containing ceramics. The incorporation of iron ions in the β-TCP lattice decreased the specific surface area as the pore size was shifted toward meso- and/or macropores. Furthermore, the human osteoblastlike cell line MG-63 was cultured onto the ceramics to determine cell proliferation and viability, and it was observed that the iron-β-TCP ceramics have better cytocompatibility than pure β-TCP. Finally, in vivo assays were performed using rabbit calvaria as a bone model. The scaffolds were implanted for 8 and 12 weeks in the defects created in the skullcap with pure β-TCP as the control. The in vivo behavior, in terms of new bone formed, degradation, and residual graft material were investigated using sequential histological evaluations and histomorphometric analysis. The in vivo implantation of the ceramics showed enhanced bone tissue formation and scaffold degradation for iron-β-TCPs. Thus, iron appears to be a useful tool to enhance the osteoconductive properties of calcium phosphate ceramics.

  5. Polymer powder processing of cryomilled polycaprolactone for solvent-free generation of homogeneous bioactive tissue engineering scaffolds.

    PubMed

    Lim, Jing; Chong, Mark Seow Khoon; Chan, Jerry Kok Yen; Teoh, Swee-Hin

    2014-06-25

    Synthetic polymers used in tissue engineering require functionalization with bioactive molecules to elicit specific physiological reactions. These additives must be homogeneously dispersed in order to achieve enhanced composite mechanical performance and uniform cellular response. This work demonstrates the use of a solvent-free powder processing technique to form osteoinductive scaffolds from cryomilled polycaprolactone (PCL) and tricalcium phosphate (TCP). Cryomilling is performed to achieve micrometer-sized distribution of PCL and reduce melt viscosity, thus improving TCP distribution and improving structural integrity. A breakthrough is achieved in the successful fabrication of 70 weight percentage of TCP into a continuous film structure. Following compaction and melting, PCL/TCP composite scaffolds are found to display uniform distribution of TCP throughout the PCL matrix regardless of composition. Homogeneous spatial distribution is also achieved in fabricated 3D scaffolds. When seeded onto powder-processed PCL/TCP films, mesenchymal stem cells are found to undergo robust and uniform osteogenic differentiation, indicating the potential application of this approach to biofunctionalize scaffolds for tissue engineering applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. A TCP/IP framework for ethernet-based measurement, control and experiment data distribution

    NASA Astrophysics Data System (ADS)

    Ocaya, R. O.; Minny, J.

    2010-11-01

    A complete modular but scalable TCP/IP based scientific instrument control and data distribution system has been designed and realized. The system features an IEEE 802.3 compliant 10 Mbps Medium Access Controller (MAC) and Physical Layer Device that is suitable for the full-duplex monitoring and control of various physically widespread measurement transducers in the presence of a local network infrastructure. The cumbersomeness of exchanging and synchronizing data between the various transducer units using physical storage media led to the choice of TCP/IP as a logical alternative. The system and methods developed are scalable for broader usage over the Internet. The system comprises a PIC18f2620 and ENC28j60 based hardware and a software component written in C, Java/Javascript and Visual Basic.NET programming languages for event-level monitoring and browser user-interfaces respectively. The system exchanges data with the host network through IPv4 packets requested and received on a HTTP page. It also responds to ICMP echo, UDP and ARP requests through a user selectable integrated DHCP and static IPv4 address allocation scheme. The round-trip time, throughput and polling frequency are estimated and reported. A typical application to temperature monitoring and logging is also presented.

  7. Sleep Deprivation Impairs and Caffeine Enhances My Performance, but Not Always Our Performance

    PubMed Central

    Faber, Nadira S.; Häusser, Jan A.; Kerr, Norbert L.

    2016-01-01

    What effects do factors that impair or enhance performance in individuals have when these individuals act in groups? We provide a framework, called the GIE ("Effects of Grouping on Impairments and Enhancements”) framework, for investigating this question. As prominent examples for individual-level impairments and enhancements, we discuss sleep deprivation and caffeine. Based on previous research, we derive hypotheses on how they influence performance in groups, specifically process gains and losses in motivation, individual capability, and coordination. We conclude that the effect an impairment or enhancement has on individual-level performance is not necessarily mirrored in group performance: grouping can help or hurt. We provide recommendations on how to estimate empirically the effects individual-level performance impairments and enhancements have in groups. By comparing sleep deprivation to stress and caffeine to pharmacological cognitive enhancement, we illustrate that we cannot readily generalize from group results on one impairment or enhancement to another, even if they have similar effects on individual-level performance. PMID:26468077

  8. Visual performance-based image enhancement methodology: an investigation of contrast enhancement algorithms

    NASA Astrophysics Data System (ADS)

    Neriani, Kelly E.; Herbranson, Travis J.; Reis, George A.; Pinkus, Alan R.; Goodyear, Charles D.

    2006-05-01

    While vast numbers of image enhancing algorithms have already been developed, the majority of these algorithms have not been assessed in terms of their visual performance-enhancing effects using militarily relevant scenarios. The goal of this research was to apply a visual performance-based assessment methodology to evaluate six algorithms that were specifically designed to enhance the contrast of digital images. The image enhancing algorithms used in this study included three different histogram equalization algorithms, the Autolevels function, the Recursive Rational Filter technique described in Marsi, Ramponi, and Carrato1 and the multiscale Retinex algorithm described in Rahman, Jobson and Woodell2. The methodology used in the assessment has been developed to acquire objective human visual performance data as a means of evaluating the contrast enhancement algorithms. Objective performance metrics, response time and error rate, were used to compare algorithm enhanced images versus two baseline conditions, original non-enhanced images and contrast-degraded images. Observers completed a visual search task using a spatial-forcedchoice paradigm. Observers searched images for a target (a military vehicle) hidden among foliage and then indicated in which quadrant of the screen the target was located. Response time and percent correct were measured for each observer. Results of the study and future directions are discussed.

  9. Detecting Subsidence Along a High Speed Railway by Ultrashort Baseline TCP-InSAR with High Resolution Images

    NASA Astrophysics Data System (ADS)

    Dai, K. R.; Liu, G. X.; Yu, B.; Jia, H. G.; Ma, D. Y.; Wang, X. W.

    2013-10-01

    A High Speed Railway goes across Wuqing district of Tianjin, China. Historical studies showed that the land subsidence of this area was very serious, which would give rise to huge security risk to the high speed railway. For detecting the detailed subsidence related to the high speed railway, we use the multi-temporal InSAR (MT-InSAR) technique to extract regional scale subsidence of Wuqing district. Take it into consideration that Wuqing district is a suburban region with large area of low coherence farmland, we select the temporarily coherent point InSAR (TCP-InSAR) approach for MT-InSAR analysis. The TCP-InSAR is a potential approach for detecting land subsidence in low coherence areas as it can identify and analysis coherent points between just two images and can acquire a reliable solution without conventional phase unwrapping. This paper extended the TCP-InSAR with use of ultrashort spatial baseline (USB) interferograms. As thetopographic effects are negligible in the USB interferograms, an external digital elevation model (DEM) is no longer needed in interferometric processing, and the parameters needed to be estimated were simplified at the same time. With use of 17 TerraSAR-X (TSX) images acquired from 2009 to 2010 over Wuqing district, the annual subsidence rates along the high speed railway were derived by the USB-TCPInSAR approach. Two subsidence funnels were found at ShuangJie town and around Wuqing Station with subsidence rate of -17 ∼ -27 mm/year and -7 ∼ -17 mm/year, respectively. The subsidence rates derived by USB-TCPInSAR were compared with those derived by the conventional TCP-InSAR that uses an external DEM for differential interferometry. The mean and the standard deviation of the differences between two types of results at 370697 TCPs are -4.43 × 10-6 mm/year and ±1.4673 mm/year, respectively. Further comparison with the subsidence results mentioned in several other studies were made, which shows good consistencies. The results

  10. β-tricalcium phosphate composite ceramics with high compressive strength, enhanced osteogenesis and inhibited osteoclastic activities.

    PubMed

    Tian, Ye; Lu, Teliang; He, Fupo; Xu, Yubin; Shi, Haishan; Shi, Xuetao; Zuo, Fei; Wu, Shanghua; Ye, Jiandong

    2018-04-13

    β-tricalcium phosphate (β-TCP) is well known as a resorbable bone repair material due to its inherent excellent biocompatibility and osteoconductivity. However, β-TCP is encountered with osteostimulation-deficiency and poor mechanical strength because of poor sinterability. Herein, we prepared novel β-TCP composite ceramics (TCP/SPGs) by introducing strontium-containing phosphate-based glass (SPG; 45P 2 O 5 -32SrO-23Na 2 O) as sintering additive. The SPG helped to achieve efficient liquid-phase sintering of β-TCP at 1100 °C. The compressive strength of TCP/SPGs with 15 wt.% SPG (TCP/SPG15) was 2.65 times as high as that of plain β-TCP ceramic. The SPG reacted with β-TCP, and the Sr 2+ and Na 2+ from SPG replaced Ca 2+ in the lattice structure of β-TCP, enabling the sustained release of strontium from TCP/SPGs. In vitro cytological test indicated that TCP/SPGs with certain amount of SPG were highly biocompatible, and noticeably promoted osteogenesis, and inhibited osteoclastic activities. Our results suggested that the TCP/SPG15 might be potential high-strength bone grafts used for bone defect repair, especially in the osteoporotic condition. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Healing bone lesion defects using injectable CaSO4 /CaPO4 -TCP bone graft substitute compared to cancellous allograft bone chips in a canine model.

    PubMed

    Hall, Deborah J; Turner, Thomas M; Urban, Robert M

    2018-04-16

    CaSO 4 /CaPO 4 -TCP bone graft substitute has been shown to be effective for treatment of bone lesion defects, but its mechanical, histological, and radiographic characteristics have not been studied in direct comparison with a conventional treatment such as cancellous allograft bone. Thirteen canines had a critical-size axial defect created bilaterally into the proximal humerus. CaSO 4 /CaPO 4 -TCP bone graft substitute (PRO-DENSE™, Wright Medical Technology) was injected into the defect in one humerus, and an equal volume of freeze-dried cancellous allograft bone chips was placed in the contralateral defect. The area fraction of new bone, residual graft, and fibrous tissue and the compressive strength and elastic modulus of bone within the defects were determined after 6, 13, or 26 weeks and correlated with radiographic changes. The data were analyzed using Friedman and Mann-Whitney tests. There was more bone in defects treated with the CaSO 4 /CaPO 4 -TCP bone graft substitute compared to defects treated with cancellous bone allograft at all three time points, and the difference at 13 weeks was significant (p = 0.025). The new bone was significantly stronger and stiffer in defects treated with the CaSO 4 /CaPO 4 -TCP bone graft substitute compared to defects treated with cancellous bone allograft at 13 (p = 0.046) and 26 weeks (p = 0.025). At 26 weeks, all defects treated with CaSO 4 /CaPO 4 -TCP bone graft substitute demonstrated complete healing with new bone, whereas healing was incomplete in all defects treated with cancellous allograft chips. The CaSO 4 /CaPO 4 -TCP bone graft substitute could provide faster and significantly stronger healing of bone lesions compared to the conventional treatment using freeze-dried cancellous allograft bone. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 Wiley Periodicals, Inc.

  12. Promoter mapping of the mouse Tcp-10bt gene in transgenic mice identifies essential male germ cell regulatory sequences.

    PubMed

    Ewulonu, U K; Snyder, L; Silver, L M; Schimenti, J C

    1996-03-01

    Transgenic mice were generated to localize essential promoter elements in the mouse testis-expressed Tcp-10 genes. These genes are expressed exclusively in male germ cells, and exhibit a diffuse range of transcriptional start sites, possibly due to the absence of a TATA box. A series of transgene constructs containing different amounts of 5' flanking DNA revealed that all sequences necessary for appropriate temporal and tissue-specific transcription of Tcp-10 reside between positions -1 to -973. All transgenic animals containing these sequences expressed a chimeric transgene at high levels, in a pattern that paralleled the endogenous genes. These experiments further defined a 227 bp fragment from -746 to -973 that was absolutely essential for expression. In a gel-shift assay, this 227-bp fragment bound nuclear protein from testis, but not other tissues, to yield two retarded bands. Sequence analysis of this fragment revealed a half-site for the AP-2 transcription factor recognition sequence. Gel shift assays using native or mutant oligonucleotides demonstrated that the putative AP-2 recognition sequence was essential for generating the retarded bands. Since the binding activity is testis-specific, but AP-2 expression is not exclusive to male germ cells, it is possible that transcription of Tcp-10 requires interaction between AP-2 and a germ cell-specific transcription factor.

  13. ATAMM enhancement and multiprocessor performance evaluation

    NASA Technical Reports Server (NTRS)

    Stoughton, John W.; Mielke, Roland R.; Som, Sukhamoy; Obando, Rodrigo; Malekpour, Mahyar R.; Jones, Robert L., III; Mandala, Brij Mohan V.

    1991-01-01

    ATAMM (Algorithm To Architecture Mapping Model) enhancement and multiprocessor performance evaluation is discussed. The following topics are included: the ATAMM model; ATAMM enhancement; ADM (Advanced Development Model) implementation of ATAMM; and ATAMM support tools.

  14. Ridge Preservation After Maxillary Third Molar Extraction Using 30% Porosity PLGA/HA/β-TCP Scaffolds With and Without Simvastatin: A Pilot Randomized Controlled Clinical Trial.

    PubMed

    Noronha Oliveira, Miguel; Rau, Levy Hermes; Marodin, Aline; Corrêa, Márcio; Corrêa, Letícia Ruhland; Aragones, Aguedo; Magini, Ricardo de Souza

    2017-12-01

    To evaluate clinically and radiographically, in humans, the healing of maxillary third molars postextraction sockets after application of different ridge preservation techniques 3 months after tooth extraction. Twenty-six sockets (13 patients) were randomly assigned to 4 treatment modalities: deproteinized bovine bone mineral with 10% collagen (DBBM-C), poly(D,L-lactide-co-glycolide) with hydroxyapatite/β-TCP scaffold (PLGA/HA), PLGA/HA/β-TCP with 2.0% simvastatin scaffold (PLGA/HA/S), and spontaneous healing (control). Clinical complications were assessed, and cone-beam computed tomographies were taken in 5 patients 3 months after surgeries. For statistical purposes, the Fisher exact test was used (P < 0.05). After 3 months, 6 of 9 grafts from the PLGA/HA group were lost (P < 0.05). PLGA/HA/S' loss was only 2 of 8 (P > 0.05), but no loss was observed in the DBBM-C group. Pain was present in 3 of 8 sites that lost the graft (37.5%) (P > 0.05) and infection in 1 of 8 (12.5%) (P > 0.05), with these only occurring in the PLGA/HA group. Poly (D, L-lactide-co-glycolide) with hydroxyapatite/β-TCP (PLGA/HA/β-TCP) scaffolds, with and without simvastatin, failed to obtain the initial expected results and presented more complications. Scaffolds with simvastatin showed to be superior, with less clinical complications than scaffolds without simvastatin.

  15. Network and User-Perceived Performance of Web Page Retrievals

    NASA Technical Reports Server (NTRS)

    Kruse, Hans; Allman, Mark; Mallasch, Paul

    1998-01-01

    The development of the HTTP protocol has been driven by the need to improve the network performance of the protocol by allowing the efficient retrieval of multiple parts of a web page without the need for multiple simultaneous TCP connections between a client and a server. We suggest that the retrieval of multiple page elements sequentially over a single TCP connection may result in a degradation of the perceived performance experienced by the user. We attempt to quantify this perceived degradation through the use of a model which combines a web retrieval simulation and an analytical model of TCP operation. Starting with the current HTTP/l.1 specification, we first suggest a client@side heuristic to improve the perceived transfer performance. We show that the perceived speed of the page retrieval can be increased without sacrificing data transfer efficiency. We then propose a new client/server extension to the HTTP/l.1 protocol to allow for the interleaving of page element retrievals. We finally address the issue of the display of advertisements on web pages, and in particular suggest a number of mechanisms which can make efficient use of IP multicast to send advertisements to a number of clients within the same network.

  16. Superparamagnetic enhancement of thermoelectric performance.

    PubMed

    Zhao, Wenyu; Liu, Zhiyuan; Sun, Zhigang; Zhang, Qingjie; Wei, Ping; Mu, Xin; Zhou, Hongyu; Li, Cuncheng; Ma, Shifang; He, Danqi; Ji, Pengxia; Zhu, Wanting; Nie, Xiaolei; Su, Xianli; Tang, Xinfeng; Shen, Baogen; Dong, Xiaoli; Yang, Jihui; Liu, Yong; Shi, Jing

    2017-09-13

    The ability to control chemical and physical structuring at the nanometre scale is important for developing high-performance thermoelectric materials. Progress in this area has been achieved mainly by enhancing phonon scattering and consequently decreasing the thermal conductivity of the lattice through the design of either interface structures at nanometre or mesoscopic length scales or multiscale hierarchical architectures. A nanostructuring approach that enables electron transport as well as phonon transport to be manipulated could potentially lead to further enhancements in thermoelectric performance. Here we show that by embedding nanoparticles of a soft magnetic material in a thermoelectric matrix we achieve dual control of phonon- and electron-transport properties. The properties of the nanoparticles-in particular, their superparamagnetic behaviour (in which the nanoparticles can be magnetized similarly to a paramagnet under an external magnetic field)-lead to three kinds of thermoelectromagnetic effect: charge transfer from the magnetic inclusions to the matrix; multiple scattering of electrons by superparamagnetic fluctuations; and enhanced phonon scattering as a result of both the magnetic fluctuations and the nanostructures themselves. We show that together these effects can effectively manipulate electron and phonon transport at nanometre and mesoscopic length scales and thereby improve the thermoelectric performance of the resulting nanocomposites.

  17. Gene doping: a review of performance-enhancing genetics.

    PubMed

    Gaffney, Gary R; Parisotto, Robin

    2007-08-01

    Unethical athletes and their mentors have long arrogated scientific and medical advances to enhance athletic performance, thus gaining a dishonest competitive advantage. Building on advances in genetics, a new threat arises from athletes using gene therapy techniques in the same manner that some abused performance-enhancing drugs were used. Gene doping, as this is known, may produce spectacular physiologic alterations to dramatically enhance athletic abilities or physical appearance. Furthermore, gene doping may present pernicious problems for the regulatory agencies and investigatory laboratories that are entrusted to keep sporting events fair and ethical. Performance-enhanced genetics will likewise present unique challenges to physicians in many spheres of their practice.

  18. Swift observation of Nova Ophiuchi 2018 No.2 = PNV J17140261-2849237 = TCP J17140253-2849233

    NASA Astrophysics Data System (ADS)

    Sokolovsky, K.

    2018-03-01

    The nova candidate PNV J17140261-2849237 = TCP J17140253-2849233 was discovered by H. Nishimura, T. Kojima, K. Nishiyama and F. Kabashima. A. Takao reports the transient (9.5mag) visible at unfiltered images obtained on 2018-03-10.753 UT. Spectroscopic observations with the 2m Liverpool Telescope confirmed the transient to be a Fe II type nova (ATel #11398).

  19. The synthesis of branched TCP chromophores and the research on their electro-optical properties

    NASA Astrophysics Data System (ADS)

    Bo, Shuhui; Chen, Zhuo; Gao, Wu; Zhen, Zhen; Liu, Xinhou

    2012-10-01

    In order to minimize the intermolecular electrostatic interactions and effectively translate high value of chromophore into macroscopic electro-optical (EO) coeffcient (r33), the shape-modification of aniline-pyrroline (TCP) chromophore by combining three kinds of dendritic groups respectively to the N atom of pyrroline acceptor produced three kinds of dendritic chromophores. Their spherical structures can minimize intermolecular electrostatic interactions, and thus the poling efficience was higher than the chromophores without dendritic groups when chromophores as a guest in the host polymer APC. A large electro-optical (EO) coefficient was achieved as high as 75 pm/V at 1315 nm with 9% chromophores loading in APC film. On the basis of the above TCP chromophores, two kinds of novel molecular glasses based on self-assembly dendritic chromophores are also designed and synthesized as second-order nonlinear optical (NLO) materials, which named ETO and ETF. The NLO chromophore glasses ETO and ETF showed excellent filmforming ability by themselves. Their glass transition temperatures (Tg) were determined at 41° and 39°, respectively. The in-situ second harmonic generation (SHG) measurement revealed the resonant electro-optical (EO) coefficient (d33) values of 38 and 32 pm/V for the poled films of ETO and ETF, respectively. The results indicate molecular glasses provide a new possible way different from the conventional polymer approach to prepare second-order NLO materials.

  20. An effector of apple proliferation phytoplasma targets TCP transcription factors-a generalized virulence strategy of phytoplasma?

    PubMed

    Janik, Katrin; Mithöfer, Axel; Raffeiner, Margot; Stellmach, Hagen; Hause, Bettina; Schlink, Katja

    2017-04-01

    The plant pathogen Candidatus Phytoplasma mali (P. mali) is the causative agent of apple proliferation, a disease of increasing importance in apple-growing areas within Europe. Despite its economic importance, little is known about the molecular mechanisms of disease manifestation within apple trees. In this study, we identified two TCP (TEOSINTE BRANCHED/CYCLOIDEA/PROLIFERATING CELL FACTOR) transcription factors of Malus x domestica as binding partners of the P. mali SAP11-like effector ATP_00189. Phytohormone analyses revealed an effect of P. mali infection on jasmonates, salicylic acid and abscisic acid levels, showing that P. mali affects phytohormonal levels in apple trees, which is in line with the functions of the effector assumed from its binding to TCP transcription factors. To our knowledge, this is the first characterization of the molecular targets of a P. mali effector and thus provides the basis to better understand symptom development and disease progress during apple proliferation. As SAP11 homologues are found in several Phytoplasma species infecting a broad range of different plants, SAP11-like proteins seem to be key players in phytoplasmal infection. © 2016 BSPP AND JOHN WILEY & SONS LTD.

  1. ENHANCING REMINERALIZATION OF PRIMARY ENAMEL LESIONS WITH FLUORIDE DENTIFRICE CONTAINING TRICALCIUM PHOSPHATE.

    PubMed

    Rirattanapong, Praphasri; Vongsavan, Kadkao; Saengsirinavin, Chavengkiat; Waidee, Sumana

    2017-03-01

    shallower than the other groups (p=0.006). There was no significant difference in the mean demineralized lesion depth between Groups B and C (p=0.478). The mean demineralized lesion depth changed significantly after dentifrice treatment in all the groups (p=0.00). Group A was significantly deeper (p=0.00) and groups B, C and D were all significantly shallow. Group D had the greatest reduction in mean demineralized lesion depth (p<0.05). The 1,000 ppm fluoride plus TCP dentifrice gave superior remineralization than the 500 ppm fluoride plus TCP and the 1,000 ppm fluoride dentifrice. The 500 ppm fluoride plus TCP gave the same remineralizing effect as the 1,000 ppm fluoride dentifrice. TCP enhances remineralization on primary enamel when added to fluoride dentifrice. Our results show if TCP is added to fluoride dentifrice a lower concentration of fluoride is needed to provide the same benefit as fluoride dentifrice with a higher concentration of fluoride, reducing the risk of fluorosis in children.

  2. 3D Porous Architecture of Stacks of β-TCP Granules Compared with That of Trabecular Bone: A microCT, Vector Analysis, and Compression Study.

    PubMed

    Chappard, Daniel; Terranova, Lisa; Mallet, Romain; Mercier, Philippe

    2015-01-01

    The 3D arrangement of porous granular biomaterials usable to fill bone defects has received little study. Granular biomaterials occupy 3D space when packed together in a manner that creates a porosity suitable for the invasion of vascular and bone cells. Granules of beta-tricalcium phosphate (β-TCP) were prepared with either 12.5 or 25 g of β-TCP powder in the same volume of slurry. When the granules were placed in a test tube, this produced 3D stacks with a high (HP) or low porosity (LP), respectively. Stacks of granules mimic the filling of a bone defect by a surgeon. The aim of this study was to compare the porosity of stacks of β-TCP granules with that of cores of trabecular bone. Biomechanical compression tests were done on the granules stacks. Bone cylinders were prepared from calf tibia plateau, constituted high-density (HD) blocks. Low-density (LD) blocks were harvested from aged cadaver tibias. Microcomputed tomography was used on the β-TCP granule stacks and the trabecular bone cores to determine porosity and specific surface. A vector-projection algorithm was used to image porosity employing a frontal plane image, which was constructed line by line from all images of a microCT stack. Stacks of HP granules had porosity (75.3 ± 0.4%) and fractal lacunarity (0.043 ± 0.007) intermediate between that of HD (respectively 69.1 ± 6.4%, p < 0.05 and 0.087 ± 0.045, p < 0.05) and LD bones (respectively 88.8 ± 1.57% and 0.037 ± 0.014), but exhibited a higher surface density (5.56 ± 0.11 mm(2)/mm(3) vs. 2.06 ± 0.26 for LD, p < 0.05). LP granular arrangements created large pores coexisting with dense areas of material. Frontal plane analysis evidenced a more regular arrangement of β-TCP granules than bone trabecule. Stacks of HP granules represent a scaffold that resembles trabecular bone in its porous microarchitecture.

  3. Carbothermic Reduction Kinetics of Phosphorous Vaporization from Tri-calcium Phosphate (TCP) Under Microwave Rapid Heating With/Without the Presence of Fe3O4

    NASA Astrophysics Data System (ADS)

    Yoshikawa, Noboru; Sunako, Manami; Kawahira, Keita; Suzuki, Koki; Miyamoto, Kazunori; Taniguchi, Shoji

    2018-06-01

    The kinetics of vapor phase dephosphorization from tri-calcium phosphate (TCP) by carbothermic reduction was studied with and without the presence of Fe3O4. Microwave heating was utilized to obtain large variations in the heating rate (HR). In the reduction of TCP alone, the phosphorous removal fraction (RF; equal to ΔP2O5/P2O 5 0 , where ΔP2O5 is the weight change and P2O 5 0 is the P2O5 weight before heating) decreased as the HR increased. In other words, a shorter residence time at a high temperature resulted in a smaller reduction fraction of TCP. An apparently third-order reaction was postulated to account for the kinetics using a fitting simulation based on the additive law of the reaction progress. On the other hand, the phosphorous removal (dephosphorization) rate (RR; equal to ΔP2O3/ t MW, where tMW is the microwave heating time period) increased as the HR increased above 1200 °C. The reduction ratio of Fe3O4 above 1100 °C is higher than 97 pct regardless of the heating rate. The reduction of TCP in the presence of Fe3O4 showed that RF increased slightly with increasing HR despite a shorter residence time at a high temperature. The RR also increased with the HR even though RF decreased to half of the values observed in the cases without Fe3O4 for temperatures above 1200 °C. The practicality and optimal operation conditions of phosphorus vapor removal were discussed.

  4. Judgments about illegal performance-enhancing substances: reasoned, reactive, or both?

    PubMed

    Dodge, Tonya; Stock, Michelle; Litt, Dana

    2013-07-01

    This study applied aspects of the Theory of Reasoned Action and the Prototype/Willingness model to understand cognitions associated with the use of illegal performance-enhancing substances. There were two study objectives. One was to investigate whether the illegal-is-effective heuristic (i.e. belief that illegal performance-enhancing substances are more effective than legal performance-enhancing substances) affects willingness to use illegal performance-enhancing substances. The second was to examine whether attitudes, norms, and prototypes influence the willingness and intentions to use illegal performance-enhancing substances. The illegal-is-effective heuristic was a significant predictor of willingness but was not a significant predictor of intentions. Implications for future research and prevention efforts are discussed.

  5. Modeling the effects of contrast enhancement on target acquisition performance

    NASA Astrophysics Data System (ADS)

    Du Bosq, Todd W.; Fanning, Jonathan D.

    2008-04-01

    Contrast enhancement and dynamic range compression are currently being used to improve the performance of infrared imagers by increasing the contrast between the target and the scene content, by better utilizing the available gray levels either globally or locally. This paper assesses the range-performance effects of various contrast enhancement algorithms for target identification with well contrasted vehicles. Human perception experiments were performed to determine field performance using contrast enhancement on the U.S. Army RDECOM CERDEC NVESD standard military eight target set using an un-cooled LWIR camera. The experiments compare the identification performance of observers viewing linearly scaled images and various contrast enhancement processed images. Contrast enhancement is modeled in the US Army thermal target acquisition model (NVThermIP) by changing the scene contrast temperature. The model predicts improved performance based on any improved target contrast, regardless of feature saturation or enhancement. To account for the equivalent blur associated with each contrast enhancement algorithm, an additional effective MTF was calculated and added to the model. The measured results are compared with the predicted performance based on the target task difficulty metric used in NVThermIP.

  6. Mathematical Difficulty: Does Early Intervention Enhance Mathematical Performance?

    ERIC Educational Resources Information Center

    Graham, Jennifer

    2008-01-01

    The need to ask educators about their opinions on the subject to what extent early intervention methods enhance mathematical performance is long overdue. The purpose of this quantitative research is to examine the extent to which teachers agree that early intervention methods enhance the mathematical performance of students with mathematical…

  7. Bone regeneration of critical calvarial defect in goat model by PLGA/TCP/rhBMP-2 scaffolds prepared by low-temperature rapid-prototyping technology.

    PubMed

    Yu, D; Li, Q; Mu, X; Chang, T; Xiong, Z

    2008-10-01

    Active artificial bone composed of poly lactide-co-glycolide (PLGA)/ tricalcium phosphate (TCP) was prefabricated using low-temperature rapid-prototyping technology so that the process of osteogenesis could be observed in it. PLGA and TCP were the primary materials, they were molded at low temperature, then recombinant human bone morphogenetic protein-2 (rhBMP-2) was added to form an active artificial bone. Goats with standard cranial defects were randomly divided into experimental (implants with rhBMP-2 added) and control (implants without rhBMP-2) groups, and osteogenesis was observed and evaluated by imaging and biomechanical and histological examinations. The PLGA-TCP artificial bone scaffold (90% porosity) had large and small pores of approximately 360microm and 3-5microm diameter. Preliminary and complete repair of the cranial defect in the goats occurred 12 and 24 weeks after surgery, respectively. The three-point bending strength of the repaired defects attained that of the normal cranium. In conclusion, low-temperature rapid-prototyping technology can preserve the biological activity of this scaffold material. The scaffold has a good three-dimensional structure and it becomes an active artificial bone after loading with rhBMP-2 with a modest degradation rate and excellent osteogenesis in the goat.

  8. Sensorimotor Rhythm Neurofeedback Enhances Golf Putting Performance.

    PubMed

    Cheng, Ming-Yang; Huang, Chung-Ju; Chang, Yu-Kai; Koester, Dirk; Schack, Thomas; Hung, Tsung-Min

    2015-12-01

    Sensorimotor rhythm (SMR) activity has been related to automaticity during skilled action execution. However, few studies have bridged the causal link between SMR activity and sports performance. This study investigated the effect of SMR neurofeedback training (SMR NFT) on golf putting performance. We hypothesized that preelite golfers would exhibit enhanced putting performance after SMR NFT. Sixteen preelite golfers were recruited and randomly assigned into either an SMR or a control group. Participants were asked to perform putting while electroencephalogram (EEG) was recorded, both before and after intervention. Our results showed that the SMR group performed more accurately when putting and exhibited greater SMR power than the control group after 8 intervention sessions. This study concludes that SMR NFT is effective for increasing SMR during action preparation and for enhancing golf putting performance. Moreover, greater SMR activity might be an EEG signature of improved attention processing, which induces superior putting performance.

  9. Using a CLIPS expert system to automatically manage TCP/IP networks and their components

    NASA Technical Reports Server (NTRS)

    Faul, Ben M.

    1991-01-01

    A expert system that can directly manage networks components on a Transmission Control Protocol/Internet Protocol (TCP/IP) network is described. Previous expert systems for managing networks have focused on managing network faults after they occur. However, this proactive expert system can monitor and control network components in near real time. The ability to directly manage network elements from the C Language Integrated Production System (CLIPS) is accomplished by the integration of the Simple Network Management Protocol (SNMP) and a Abstract Syntax Notation (ASN) parser into the CLIPS artificial intelligence language.

  10. Optical Spectroscopy of TCP J04432130+4721280 (V392 Per) Confirms a Nova Eruption

    NASA Astrophysics Data System (ADS)

    Wagner, R. M.; Terndrup, D.; Darnley, M. J.; Starrfield, S.; Woodward, C. E.; Henze, M.

    2018-04-01

    Following reports of a new transient of magnitude 6.2 in Perseus on 2018 April 29.4740 UT discovered by Y. Nakamura designated TCP J04432130+4721280 (http://www.cbat.eps.harvard.edu/unconf/followups/J04432130+4721280.html) and positionally coincident with the previously known U Gem type dwarf nova V392 Per, we obtained an optical spectrum on 2018 April 30.116 UT (range: 396-687 nm; resolution 0.3 nm) with the 2.4 m Hiltner telescope (+OSMOS) of the MDM Observatory on Kitt Peak.

  11. Enhanced In Vivo Bone and Blood Vessel Formation by Iron Oxide and Silica Doped 3D Printed Tricalcium Phosphate Scaffolds.

    PubMed

    Bose, Susmita; Banerjee, Dishary; Robertson, Samuel; Vahabzadeh, Sahar

    2018-05-04

    Calcium phosphate (CaP) ceramics show significant promise towards bone graft applications because of the compositional similarity to inorganic materials of bone. With 3D printing, it is possible to create ceramic implants that closely mimic the geometry of human bone and can be custom-designed for unusual injuries or anatomical sites. The objective of the study was to optimize the 3D-printing parameters for the fabrication of scaffolds, with complex geometry, made from synthesized tricalcium phosphate (TCP) powder. This study was also intended to elucidate the mechanical and biological effects of the addition of Fe +3 and Si +4 in TCP implants in a rat distal femur model for 4, 8, and 12 weeks. Doped with Fe +3 and Si +4 TCP scaffolds with 3D interconnected channels were fabricated to provide channels for micronutrients delivery and improved cell-material interactions through bioactive fixation. Addition of Fe +3 into TCP enhanced early-stage new bone formation by increasing type I collagen production. Neovascularization was observed in the Si +4 doped samples after 12 weeks. These findings emphasize that the additive manufacturing of scaffolds with complex geometry from synthesized ceramic powder with modified chemistry is feasible and may serve as a potential candidate to introduce angiogenic and osteogenic properties to CaPs, leading to accelerated bone defect healing.

  12. Peripheral visual performance enhancement by neurofeedback training.

    PubMed

    Nan, Wenya; Wan, Feng; Lou, Chin Ian; Vai, Mang I; Rosa, Agostinho

    2013-12-01

    Peripheral visual performance is an important ability for everyone, and a positive inter-individual correlation is found between the peripheral visual performance and the alpha amplitude during the performance test. This study investigated the effect of alpha neurofeedback training on the peripheral visual performance. A neurofeedback group of 13 subjects finished 20 sessions of alpha enhancement feedback within 20 days. The peripheral visual performance was assessed by a new dynamic peripheral visual test on the first and last training day. The results revealed that the neurofeedback group showed significant enhancement of the peripheral visual performance as well as the relative alpha amplitude during the peripheral visual test. It was not the case in the non-neurofeedback control group, which performed the tests within the same time frame as the neurofeedback group but without any training sessions. These findings suggest that alpha neurofeedback training was effective in improving peripheral visual performance. To the best of our knowledge, this is the first study to show evidence for performance improvement in peripheral vision via alpha neurofeedback training.

  13. BMP-7 Preserves Surface Integrity of Degradable-ceramic Cranioplasty in a Göttingen Minipig Model

    PubMed Central

    Schulz, Peter; Klünter, Tim; Deisinger, Ulrike; Diez, Claudius; Waiss, Waltraud; Kirschneck, Christian; Reichert, Torsten E.; Detsch, Rainer

    2017-01-01

    Background: The aim of the study was to evaluate the integrity of a craniotomy grafted site in a minipig model using different highly porous calcium phosphate ceramic scaffolds either loaded or nonloaded with bone morphogenetic protein-7 (BMP-7). Methods: Four craniotomies with a diameter of 15 mm (critical-size defect) were grafted with different highly porous (92–94 vol%) calcium phosphate ceramics [hydroxyapatite (HA), tricalcium phosphate (TCP), and biphasic calcium phosphate (BCP; a mixture of HA and TCP)] in 10 Göttingen minipigs: (a) group I (n = 5): HA versus BCP; (b) group II (n = 5): TCP versus BCP. One scaffold of each composition was supplied with 250 μg of BMP-7. In vivo computed tomography scan and fluorochrome bone labeling were performed. Specimens were evaluated 14 weeks after surgery by environmental scanning electron microscopy, fluorescence microscopy, and Giemsa staining histology. Results: BMP-7 significantly enhanced bone formation in TCP (P = 0.047). Slightly enhanced bone formation was observed in BCP (P = 0.059) but not in HA implants. BMP-7 enhanced ceramic degradation in TCP (P = 0.05) and BCP (P = 0.05) implants but not in HA implants. Surface integrity of grafted site was observed in all BMP-7-loaded implants after successful creeping substitution by the newly formed bone. In 9 of 10 HA implants without BMP-7, partial collapse of the implant site was observed. All TCP implants without BMP-7 collapsed. Fluorescent labeling showed bone formation at week 1 in BMP-7-stimulated implants. Conclusions: BMP-7 supports bone formation, ceramic degradation, implant integration, and surface integrity of the grafted site. PMID:28458969

  14. Robotic hand with locking mechanism using TCP muscles for applications in prosthetic hand and humanoids

    NASA Astrophysics Data System (ADS)

    Saharan, Lokesh; Tadesse, Yonas

    2016-04-01

    This paper presents a biomimetic, lightweight, 3D printed and customizable robotic hand with locking mechanism consisting of Twisted and Coiled Polymer (TCP) muscles based on nylon precursor fibers as artificial muscles. Previously, we have presented a small-sized biomimetic hand using nylon based artificial muscles and fishing line muscles as actuators. The current study focuses on an adult-sized prosthetic hand with improved design and a position/force locking system. Energy efficiency is always a matter of concern to make compact, lightweight, durable and cost effective devices. In natural human hand, if we keep holding objects for long time, we get tired because of continuous use of energy for keeping the fingers in certain positions. Similarly, in prosthetic hands we also need to provide energy continuously to artificial muscles to hold the object for a certain period of time, which is certainly not energy efficient. In this work we, describe the design of the robotic hand and locking mechanism along with the experimental results on the performance of the locking mechanism.

  15. CONVECTION ENHANCED DELIVERY OF CARBORANYLPORPHYRINS FOR NEUTRON CAPTURE THERAPY OF BRAIN TUMORS

    PubMed Central

    Kawabata, Shinji; Yang, Weilian; Wu, Gong; Huo, Tianyao; Binns, Peter J.; Riley, Kent J.; Ongayi, Owendi; Gottumukkala, Vijay; Vicente, M. Graça H.

    2010-01-01

    Boron neutron capture therapy (BNCT) is based on the nuclear capture and fission reactions that occur when non-radioactive 10B is irradiated with low energy thermal neutrons to produce α-particles (10B[n,α]7Li). Carboranylporphyrins are a class of substituted porphyrins containing multiple carborane clusters. Three of these have been evaluated in the present study: 5,10,15,20-tetra-(4-nido-carboranyphenyl)tetrabenzoporphyrin (H2TBP), 5,10,15,20-tetra-(4-nido-carboranylphenyl)porphyrin (H2TCP) and 5,15-di-[3,5-(nido-carboranylmethyl)phenyl]-porphyrin (H2DCP). The goals of this study were two-fold. First, to determine the biodistribution of H2TBP, H2TCP and H2DCP following intracerebral (i.c.) administration by means of short term (30 min) convection enhanced delivery (CED) or sustained delivery over 24 h by osmotic pumps to F98 glioma bearing rats. Second, to determine the efficacy of H2TCP and H2TBP as boron delivery agents for BNCT in F98 glioma bearing rats. Tumor boron concentrations immediately after i.c. osmotic pump delivery were high (36–88 µg/g) and they remained so at 24 h (62–103 µg/g) The corresponding normal brain concentrations were low (0.8–5.2 µg/g) and the blood and liver concentrations were all undetectable. Based on these data, therapy studies were initiated at the Massachusetts Institute of Technology (MIT) Research Reactor (MITRR) with H2TCP and H2TBP 24 h after CED or osmotic pump delivery. Mean survival times (MST) of untreated and irradiated control rats were 23±3 and 27±3 d, respectively, while animals that received H2TCP or H2TBP, followed by BNCT, had a MST of 35±4 d and 44±10 d, respectively, which were better than those obtained following i.v. administration of boronophenylalanine (37±3 d). However, since the tumor boron concentrations of the carboranylporphyrins were 3–5X > i.v. BPA (~25 µg/g), we had expected that the MSTs would have been greater. Histopathologic examination of brains of BNCT treated rats revealed

  16. Learning, Remembering, Believing. Enhancing Human Performance.

    ERIC Educational Resources Information Center

    Druckman, Daniel, Ed.; Bjork, Robert A., Ed.

    This book is the third report of the Committee on Techniques for the Enhancement of Human Performance. Based on hundreds of research studies of learning and human performance as reported in the literature, the book consists of 11 chapters organized in five parts. The two chapters of the first part provide the background and summary of the…

  17. A novel vascular-targeting peptide for gastric cancer delivers low-dose TNFα to normalize the blood vessels and improve the anti-cancer efficiency of 5-fluorouracil.

    PubMed

    Lu, Lan; Li, Zhi Jie; Li, Long Fei; Shen, Jing; Zhang, Lin; Li, Ming Xing; Xiao, Zhan Gang; Wang, Jian Hao; Cho, Chi Hin

    2017-11-01

    Various vascular-targeted agents fused with tumor necrosis factor α (TNFα) have been shown to improve drug absorption into tumor tissues and enhance tumor vascular function. TCP-1 is a peptide selected through in vivo phage library biopanning against a mouse orthotopic colorectal cancer model and is a promising agent for drug delivery. This study further investigated the targeting ability of TCP-1 phage and peptide to blood vessels in an orthotopic gastric cancer model in mice and assessed the synergistic anti-cancer effect of 5-fluorouracil (5-FU) with subnanogram TNFα targeted delivered by TCP-1 peptide. In vivo phage targeting assay and in vivo colocalization analysis were carried out to test the targeting ability of TCP-1 phage/peptide. A targeted therapy for improvement of the therapeutic efficacy of 5-FU and vascular function was performed through administration of TCP-1/TNFα fusion protein in this model. TCP-1 phage exhibited strong homing ability to the orthotopic gastric cancer after phage injection. Immunohistochemical staining suggested that and TCP-1 phage/TCP-1 peptide could colocalize with tumor vascular endothelial cells. TCP-1/TNFα combined with 5-FU was found to synergistically inhibit tumor growth, induce apoptosis and reduce cell proliferation without evident toxicity. Simultaneously, subnanogram TCP-1/TNFα treatment normalized tumor blood vessels. Targeted delivery of low-dose TNFα by TCP-1 peptide can potentially modulate the vascular function of gastric cancer and increase the drug delivery of chemotherapeutic drugs. Copyright © 2017. Published by Elsevier Inc.

  18. Performance and reliability enhancement of linear coolers

    NASA Astrophysics Data System (ADS)

    Mai, M.; Rühlich, I.; Schreiter, A.; Zehner, S.

    2010-04-01

    Highest efficiency states a crucial requirement for modern tactical IR cryocooling systems. For enhancement of overall efficiency, AIM cryocooler designs where reassessed considering all relevant loss mechanisms and associated components. Performed investigation was based on state-of-the-art simulation software featuring magnet circuitry analysis as well as computational fluid dynamics (CFD) to realistically replicate thermodynamic interactions. As a result, an improved design for AIM linear coolers could be derived. This paper gives an overview on performance enhancement activities and major results. An additional key-requirement for cryocoolers is reliability. In recent time, AIM has introduced linear coolers with full Flexure Bearing suspension on both ends of the driving mechanism incorporating Moving Magnet piston drive. In conjunction with a Pulse-Tube coldfinger these coolers are capable of meeting MTTF's (Mean Time To Failure) in excess of 50,000 hours offering superior reliability for space applications. Ongoing development also focuses on reliability enhancement, deriving space technology into tactical solutions combining both, excelling specific performance with space like reliability. Concerned publication will summarize the progress of this reliability program and give further prospect.

  19. Investigating enhanced thermoelectric performance of graphene-based nano-structures.

    PubMed

    Hossain, Md Sharafat; Huynh, Duc Hau; Jiang, Liming; Rahman, Sharmin; Nguyen, Phuong Duc; Al-Dirini, Feras; Hossain, Faruque; Bahk, Je-Hyeong; Skafidas, Efstratios

    2018-03-08

    Recently, it has been demonstrated that graphene nano-ribbons (GNRs) exhibit superior thermoelectric performance compared to graphene sheets. However, the underlying mechanism behind this enhancement has not been systematically investigated and significant opportunity remains for further enhancement of the thermoelectric performance of GNRs by optimizing their charge carrier concentration. In this work, we modulate the carrier concentration of graphene-based nano-structures using a gate voltage and investigate the resulting carrier-concentration-dependent thermoelectric parameters using the Boltzmann transport equations. We investigate the effect of energy dependent scattering time and the role of substrate-induced charge carrier fluctuation in optimizing the Seebeck coefficient and power factor. Our approach predicts the scattering mechanism and the extent of the charge carrier fluctuation in different samples and explains the enhancement of thermoelectric performance of GNR samples. Subsequently, we propose a route towards the enhancement of thermoelectric performance of graphene-based devices which can also be applied to other two-dimensional materials.

  20. Simple shearing flow of dry soap foams with TCP structure[Tetrahedrally Close-Packed

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    REINELT,DOUGLAS A.; KRAYNIK,ANDREW M.

    2000-02-16

    The microrheology of dry soap foams subjected to large, quasistatic, simple shearing deformations is analyzed. Two different monodisperse foams with tetrahedrally close-packed (TCP) structure are examined: Weaire-Phelan (A15) and Friauf-Laves (C15). The elastic-plastic response is evaluated by calculating foam structures that minimize total surface area at each value of strain. The minimal surfaces are computed with the Surface Evolver program developed by Brakke. The foam geometry and macroscopic stress are piecewise continuous functions of strain. The stress scales as T/V{sup 1/3} where T is surface tension and V is cell volume. Each discontinuity corresponds to large changes in foam geometrymore » and topology that restore equilibrium to unstable configurations that violate Plateau's laws. The instabilities occur when the length of an edge on a polyhedral foam cell vanishes. The length can tend to zero smoothly or abruptly with strain. The abrupt case occurs when a small increase in strain changes the energy profile in the neighborhood of a foam structure from a local minimum to a saddle point, which can lead to symmetry-breaking bifurcations. In general, the new foam topology associated with each stable solution branch results from a cascade of local topology changes called T1 transitions. Each T1 cascade produces different cell neighbors, reduces surface energy, and provides an irreversible, film-level mechanism for plastic yield behavior. Stress-strain curves and average stresses are evaluated by examining foam orientations that admit strain-periodic behavior. For some orientations, the deformation cycle includes Kelvin cells instead of the original TCP structure; but the foam does not remain perfectly ordered. Bifurcations during subsequent T1 cascades lead to disorder and can even cause strain localization.« less

  1. Enhancing team-sport athlete performance: is altitude training relevant?

    PubMed

    Billaut, François; Gore, Christopher J; Aughey, Robert J

    2012-09-01

    Field-based team sport matches are composed of short, high-intensity efforts, interspersed with intervals of rest or submaximal exercise, repeated over a period of 60-120 minutes. Matches may also be played at moderate altitude where the lower oxygen partial pressure exerts a detrimental effect on performance. To enhance run-based performance, team-sport athletes use varied training strategies focusing on different aspects of team-sport physiology, including aerobic, sprint, repeated-sprint and resistance training. Interestingly, 'altitude' training (i.e. living and/or training in O(2)-reduced environments) has only been empirically employed by athletes and coaches to improve the basic characteristics of speed and endurance necessary to excel in team sports. Hypoxia, as an additional stimulus to training, is typically used by endurance athletes to enhance performance at sea level and to prepare for competition at altitude. Several approaches have evolved in the last few decades, which are known to enhance aerobic power and, thus, endurance performance. Altitude training can also promote an increased anaerobic fitness, and may enhance sprint capacity. Therefore, altitude training may confer potentially-beneficial adaptations to team-sport athletes, which have been overlooked in contemporary sport physiology research. Here, we review the current knowledge on the established benefits of altitude training on physiological systems relevant to team-sport performance, and conclude that current evidence supports implementation of altitude training modalities to enhance match physical performances at both sea level and altitude. We hope that this will guide the practice of many athletes and stimulate future research to better refine training programmes.

  2. Yes, Classroom Sales Training Can Enhance Performance.

    ERIC Educational Resources Information Center

    Graham, Steven W.; Wedman, John; Monahan, Carol; Tanner, Tom

    1998-01-01

    Discusses learning in organizations, competitiveness, and training effectiveness. Describes a study that was conducted to determine if it is possible to link sales production to participation in classroom sales training, and if so, what elements seem to be most useful in enhancing employee performance and sales performance. (Author/LRW)

  3. Synthesis and characterization of injectable composites of poly[D,L-lactide-co-(ε-caprolactone)] reinforced with β-TCP and CaCO3 for intervertebral disk augmentation.

    PubMed

    López, Alejandro; Persson, Cecilia; Hilborn, Jöns; Engqvist, Håkan

    2010-10-01

    Degeneration of the intervertebral disk constitutes one of the major causes of low back pain in adults aged 20-50 years old. In this study, injectable, in situ setting, degradable composites aimed for intervertebral disk replacement were prepared. β-TCP and calcium carbonate particles were mixed into acrylic-terminated oligo[D,L-lactide-co-(ε-caprolactone)], which were crosslinked at room temperature. The structure of the oligomers was confirmed by 1H-NMR spectroscopy. The composites were examined via SEM, and the mechanical properties of the crosslinked networks were determined. The porous β-TCP particles showed good mechanical anchorage to the matrix due to polymer penetration into the pores. In vitro degradation tests showed that the composites containing β-TCP slowly degraded, whereas the composites containing CaCO3 exhibited apatite formation capacity. It was concluded that the surface area, morphology, and solubility of the fillers might be used to control the degradation properties. The incorporation of fillers also increased both the elastic modulus and the maximum compression strength of the composites, properties that were similar to those of the physiological disk. These materials have potential for long-term intervertebral disk replacement and regenerative scaffolds because of their low degradation rates, bioactivity, and mechanical properties.

  4. WE-H-BRA-02: Radiobiological Modeling of Tumor Control Probability (TCP) and Radiation-Induced Pneumonitis (RP) for Lung Cancer Patients Treated with Monte Carlo-Based Lung SBRT

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pokhrel, D; Sood, S; Shen, X

    2016-06-15

    Purpose: To present radiobiological modeling of TCP using tumor size-adjusted BED(s-BED)and PTV(D99) to lung SBRT patients treated with X-ray Voxel Monte Carlo(XVMC) algorithm, apply parameterized Lyman-NTCP model to predict grade-2 RP and subsequently, compare with clinical outcomes/observations. Methods: Dosimetric parameters and clinical follow-up for XVMC-based lung-SBRT patients were retrospectively evaluated. Patients were treated at Novalis-TX with hybrid(2 non-coplanar partial-arcs plus 3–6 static-beams)plan using HD-MLC/6MV-SRS-beam.For TCP,s-BED modelling was utilized: TCP=EXP[sBED-TCD50]/k/(1.0+EXP[sBED-TCD50]/k), where k=31Gy corresponding to TCD50=0Gy and s-BED was defined as BED10 minus 10 times the tumor diameter(in centimeters)by Ohri et al.(IJROBP,2012). For 2-yr local-control, we used more-realistic MC-computed PTVD99 as amore » predictive parameter, s-BED(D99).Due to relatively shorter median follow-up interval(12-months),Kaplan-Meier curves were generated to estimate 2-yr observed local-control and compared to predicted-rate by TCP modeling. For NTCP, we employed parameterized Lyman-NTCP model utilizing normal-lung DVH and α/β=3Gy fitted to predict grade-2 RP after lung-SBRT. Results: Total 108 patients (137 tumors) treated for 35–70Gy in 3–5 fractions, either primary-lung(n=74)or metastatic-lung(n=53)tumors were included.F or the given prescription dose with MC-computed MUs, 2-yr local-control rates with s-BED(D99) was 87±8%. Kaplan-Meier generated observed local-control rate at 2-yr was 87.5%,suggesting that PTV(D99) could be a potential predictor (p-value=0.38). Observed vs predicted TCP for primary-lung tumors and metastatic tumors were 97% vs 88±7% and 94% vs 86±9%.NTCP model predicted well for symptomatic-RP with predicted vs observed (3±5% vs 2%). Radiographic and clinically significant RP was observed in 13% and 2% of patients. Higher rates of radiographic change were observed in patients who received >50Gy compared to

  5. A novel germ cell protein, SPIF (sperm PKA interacting factor), is essential for the formation of a PKA/TCP11 complex that undergoes conformational and phosphorylation changes upon capacitation.

    PubMed

    Stanger, Simone J; Law, Estelle A; Jamsai, Duangporn; O'Bryan, Moira K; Nixon, Brett; McLaughlin, Eileen A; Aitken, R John; Roman, Shaun D

    2016-08-01

    Spermatozoa require the process of capacitation to enable them to fertilize an egg. PKA is crucial to capacitation and the development of hyperactivated motility. Sperm PKA is activated by cAMP generated by the germ cell-enriched adenylyl cyclase encoded by Adcy10 Male mice lacking Adcy10 are sterile, because their spermatozoa are immotile. The current study was designed to identify binding partners of the sperm-specific (Cα2) catalytic subunit of PKA (PRKACA) by using it as the "bait" in a yeast 2-hybrid system. This approach was used to identify a novel germ cell-enriched protein, sperm PKA interacting factor (SPIF), in 25% of the positive clones. Homozygous Spif-null mice were embryonically lethal. SPIF was coexpressed and coregulated with PRKACA and with t-complex protein (TCP)-11, a protein associated with PKA signaling. We established that these 3 proteins form part of a novel complex in mouse spermatozoa. Upon capacitation, the SPIF protein becomes tyrosine phosphorylated in >95% of sperm. An apparent molecular rearrangement in the complex occurs, bringing PRKACA and TCP11 into proximity. Taken together, these results suggest a role for the novel complex of SPIF, PRKACA, and TCP11 during sperm capacitation, fertilization, and embryogenesis.-Stanger, S. J., Law, E. A., Jamsai, D., O'Bryan, M. K., Nixon, B., McLaughlin, E. A., Aitken, R. J., Roman, S. D. A novel germ cell protein, SPIF (sperm PKA interacting factor), is essential for the formation of a PKA/TCP11 complex that undergoes conformational and phosphorylation changes upon capacitation. © FASEB.

  6. Using Machine Learning for Behavior-Based Access Control: Scalable Anomaly Detection on TCP Connections and HTTP Requests

    DTIC Science & Technology

    2013-11-01

    machine learning techniques used in BBAC to make predictions about the intent of actors establishing TCP connections and issuing HTTP requests. We discuss pragmatic challenges and solutions we encountered in implementing and evaluating BBAC, discussing (a) the general concepts underlying BBAC, (b) challenges we have encountered in identifying suitable datasets, (c) mitigation strategies to cope...and describe current plans for transitioning BBAC capabilities into the Department of Defense together with lessons learned for the machine learning

  7. Progress and prospects: gene therapy for performance and appearance enhancement.

    PubMed

    Kiuru, M; Crystal, R G

    2008-03-01

    While medical therapies aim at reversing, reducing or eliminating diseases, the goal of enhancements is to improve performance or appearance beyond normal levels. Distinction between the two interventions is not always clear as they often present as a continuum. Gene therapy typically aims at treating or preventing disease, but the technology can theoretically be employed for enhancement. Some of the gene therapy enhancement strategies include improving performance by increasing muscle mass, endurance, memory, and cognition and bettering appearance by controlling weight, height and hair growth. In addition to the technical challenges of making enhancement strategies safe and effective, genetic enhancement presents significant ethical/societal questions that must be addressed.

  8. Bioactive borate glass promotes the repair of radius segmental bone defects by enhancing the osteogenic differentiation of BMSCs.

    PubMed

    Zhang, Jieyuan; Guan, Junjie; Zhang, Changqing; Wang, Hui; Huang, Wenhai; Guo, Shangchun; Niu, Xin; Xie, Zongping; Wang, Yang

    2015-11-20

    Bioactive borate glass (BG) has emerged as a promising alternative for bone regeneration due to its high osteoinductivity, osteoconductivity, compressive strength, and biocompatibility. However, the role of BG in large segmental bone repair is unclear and little is known about the underlying mechanism of BG's osteoinductivity. In this study, we demonstrated that BG possessed pro-osteogenic effects in an experimental model of critical-sized radius defects. Transplanting BG to radius defects resulted in better repair of bone defects as compared to widely used β-TCP. Histological and morphological analysis indicated that BG significantly enhanced new bone formation. Furthermore, the degradation rate of the BG was faster than that of β-TCP, which matched the higher bone regeneration rate. In addition, ions from BG enhanced cell viability, ALP activity, and osteogenic-related genes expression. Mechanistically, the critical genes Smad1/5 and Dlx5 in the BMP pathway and p-Smad1/5 proteins were significantly elevated after BG transplantation, and these effects could be blocked by the BMP/Smad specific inhibitor. Taken together, our findings suggest that BG could repair large segmental bone defects through activating the BMP/Smad pathway and osteogenic differentiation in BMSCs.

  9. Performance management system enhancement and maintenance

    NASA Technical Reports Server (NTRS)

    Cleaver, T. G.; Ahour, R.; Johnson, B. R.

    1984-01-01

    The research described in this report concludes a two-year effort to develop a Performance Management System (PMS) for the NCC computers. PMS provides semi-automated monthly reports to NASA and contractor management on the status and performance of the NCC computers in the TDRSS program. Throughout 1984, PMS was tested, debugged, extended, and enhanced. Regular PMS monthly reports were produced and distributed. PMS continues to operate at the NCC under control of Bendix Corp. personnel.

  10. SU-F-T-686: Considerations About Dose Protraction Factor in TCP Calculations for Prostate VMAT Treatments

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Clemente, F; Perez-Vara, C; Clavo, M

    2016-06-15

    Purpose: Dose protraction factor should be considered in order to model the TCP calculations. Nevertheless, this study describes a brief discussion showing that the lack of its inclusion should not invalidate these calculations for prostate VMAT treatments. Methods: Dose protraction factor (G) modifies the quadratic term of the linear-quadratic expression in order to take into account the sublethal damage repair of protracting the dose delivery. If the delivery takes a short time (instantaneous), G = 1. For any other dose delivery pattern, G < 1. The Lea-Catcheside dose protraction factor for external beam radiotherapy contains terms depending of on themore » tissue specific repair parameter (λ) and the irradiation time (T). Expanding the exponential term using a Taylor’s series and neglecting terms of order (λT){sup 3}, the approximation leads to G = 1. The described situation occurs for 3DCRT techniques, where treatment times are about few minutes. For IMRT techniques, fraction times are prolonged compared to 3DCRT times. Wang et al. (2003) and Fowler et al. (2004) investigated the protraction effect with respect to IMRT treatments, reporting clinically significant loss in biological effect associated with IMRT delivery times. Results: Treatment times are noticeably reduced for prostate treatments using VMAT techniques. These times are comparable to 3DCRT times, leading to consider the previous approximation. Conclusion: Dose protraction factor can be approximated by G = 1 in TCP calculations for prostate treatments using VMAT techniques.« less

  11. In the Mind's Eye: Enhancing Human Performance.

    ERIC Educational Resources Information Center

    Druckman, Daniel, Ed.; Bjork, Robert A., Ed.

    This book presents a look at methods of performance enhancement, examining basic issues of performance through a series of papers which evaluate several popular self-improvement approaches by weighing the evidence to determine what works. The first of the book's four parts provides an overview of the volume with two chapters describing the history…

  12. An extraordinary transmission analogue for enhancing microwave antenna performance

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pushpakaran, Sarin V., E-mail: sarincrema@gmail.com; Purushothaman, Jayakrishnan M.; Chandroth, Aanandan

    2015-10-15

    The theory of diffraction limit proposed by H.A Bethe limits the total power transfer through a subwavelength hole. Researchers all over the world have gone through different techniques for boosting the transmission through subwavelength holes resulting in the Extraordinary Transmission (EOT) behavior. We examine computationally and experimentally the concept of EOT nature in the microwave range for enhancing radiation performance of a stacked dipole antenna working in the S band. It is shown that the front to back ratio of the antenna is considerably enhanced without affecting the impedance matching performance of the design. The computational analysis based on Finitemore » Difference Time Domain (FDTD) method reveals that the excitation of Fabry-Perot resonant modes on the slots is responsible for performance enhancement.« less

  13. The bioethics of enhancing human performance for spaceflight

    PubMed Central

    Gibson, T M

    2006-01-01

    There are many ways of enhancing human performance. For military aviation in general, and for spaceflight in particular, the most important tools are selection, training, equipment, pharmacology, and surgery. In the future, genetic manipulation may be feasible. For each of these tools, the specific modalities available range from the ethically acceptable to the ethically unacceptable. Even when someone consents to a particular procedure to enhance performance, the action may be ethically unacceptable to society as a whole and the burden of risk for the individual may be too great. In addition, there are several characteristics that define the quality and the acceptability of the consent. Each method of enhancing performance will be examined in the context of the principles of medical ethics in a western society: autonomy, non‐maleficence, beneficence, and justice. The aim is to draw the attention of aeromedical practitioners to the complexities of ethical dilemmas such as this particular one in order to help them to develop a morally justifiable code of practice that balances society's needs against individual ambitions and corporate goals. PMID:16507654

  14. [Investigation of team processes that enhance team performance in business organization].

    PubMed

    Nawata, Kengo; Yamaguchi, Hiroyuki; Hatano, Toru; Aoshima, Mika

    2015-02-01

    Many researchers have suggested team processes that enhance team performance. However, past team process models were based on crew team, whose all team members perform an indivisible temporary task. These models may be inapplicable business teams, whose individual members perform middle- and long-term tasks assigned to individual members. This study modified the teamwork model of Dickinson and McIntyre (1997) and aimed to demonstrate a whole team process that enhances the performance of business teams. We surveyed five companies (member N = 1,400, team N = 161) and investigated team-level-processes. Results showed that there were two sides of team processes: "communication" and "collaboration to achieve a goal." Team processes in which communication enhanced collaboration improved team performance with regard to all aspects of the quantitative objective index (e.g., current income and number of sales), supervisor rating, and self-rating measurements. On the basis of these results, we discuss the entire process by which teamwork enhances team performance in business organizations.

  15. Enhancement of human cognitive performance using transcranial magnetic stimulation (TMS)

    PubMed Central

    Luber, Bruce; Lisanby, and Sarah H.

    2014-01-01

    Here we review the usefulness of transcranial magnetic stimulation (TMS) in modulating cortical networks in ways that might produce performance enhancements in healthy human subjects. To date over sixty studies have reported significant improvements in speed and accuracy in a variety of tasks involving perceptual, motor, and executive processing. Two basic categories of enhancement mechanisms are suggested by this literature: direct modulation of a cortical region or network that leads to more efficient processing, and addition-by-subtraction, which is disruption of processing which competes or distracts from task performance. Potential applications of TMS cognitive enhancement, including research into cortical function, rehabilitation therapy in neurological and psychiatric illness, and accelerated skill acquisition in healthy individuals are discussed, as are methods of optimizing the magnitude and duration of TMS-induced performance enhancement, such as improvement of targeting through further integration of brain imaging with TMS. One technique, combining multiple sessions of TMS with concurrent TMS/task performance to induce Hebbian-like learning, appears to be promising for prolonging enhancement effects. While further refinements in the application of TMS to cognitive enhancement can still be made, and questions remain regarding the mechanisms underlying the observed effects, this appears to be a fruitful area of investigation that may shed light on the basic mechanisms of cognitive function and their therapeutic modulation. PMID:23770409

  16. Temporal Control of Plant Organ Growth by TCP Transcription Factors.

    PubMed

    Huang, Tengbo; Irish, Vivian F

    2015-06-29

    The Arabidopsis petal is a simple laminar organ whose development is largely impervious to environmental effects, making it an excellent model for dissecting the regulation of cell-cycle progression and post-mitotic cell expansion that together sculpt organ form. Arabidopsis petals grow via basipetal waves of cell division, followed by a phase of cell expansion. RABBIT EARS (RBE) encodes a C2H2 zinc finger transcriptional repressor and is required for petal development. During the early phase of petal initiation, RBE regulates a microRNA164-dependent pathway that controls cell proliferation at the petal primordium boundaries. The effects of rbe mutations on petal lamina growth suggest that RBE is also required to regulate later developmental events during petal organogenesis. Here, we demonstrate that, early in petal development, RBE represses the transcription of a suite of CIN-TCP genes that in turn act to inhibit the number and duration of cell divisions; the temporal alleviation of that repression results in the transition from cell division to post-mitotic cell expansion and concomitant petal maturation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Performance Support Systems: Integrating AI, Hypermedia, and CBT to Enhance User Performance.

    ERIC Educational Resources Information Center

    McGraw, Karen L.

    1994-01-01

    Examines the use of a performance support system (PSS) to enhance user performance on an operational system. Highlights include background information that describes the stimulus for PSS development; discussion of the major PSS components and the technology they require; and discussion of the design of a PSS for a complex database system.…

  18. Female Athletes and Performance-Enhancer Usage

    ERIC Educational Resources Information Center

    Fralinger, Barbara K.; Pinto-Zipp, Genevieve; Olson, Valerie; Simpkins, Susan

    2007-01-01

    The purpose of this study was to develop a knowledge base on factors associated with performance-enhancer usage among female athletes at the high school level in order to identify markers for a future prevention-education program. The study used a pretest-only, between-subjects Likert Scale survey to rank the importance of internal and external…

  19. Does Citrulline Malate Enhance Physical Performance

    DTIC Science & Technology

    2010-10-01

    Jakeman, P.M. (2010). Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness. Journal of Strength and Conditioning...returned for their third and final VO2 max test. VO2max, lactate threshold , maximum watts reached, ratings of perceived exertion and pre- and post...7 Figure 7. Lactate threshold (as % of VO2max) for all three conditions

  20. WE-F-304-05: Cranial TCP/NTCP Modeling Insights and Caveats

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    El Naqa, I.

    Stereotactic Body Radiation Therapy (SBRT) was introduced clinically more than twenty years ago, and many subsequent publications have reported safety and efficacy data. The AAPM Working Group on Biological Effects of Hypofractionated Radiotherapy/SBRT (WGSBRT) extracted published treatment outcomes data from extensive literature searches to summarize and construct tumor control probability (TCP) and normal tissue complication probability (NTCP) models for six anatomical regions: Cranial, Head and Neck, Thoracic, Abdominal, Pelvic, and Spinal. In this session, we present the WGSBRT’s work for cranial sites, and recurrent head and neck cancer. From literature-based data and associated models, guidelines to aid with safe andmore » effective hypofractionated radiotherapy treatment are being determined. Further, the ability of existing and proposed radiobiological models to fit these data is considered as to the ability to distinguish between the linear-quadratic and alternative radiobiological models such as secondary cell death from vascular damage, immunogenic, or bystander effects. Where appropriate, specific model parameters are estimated. As described in “The lessons of QUANTEC,” (1), lack of adequate reporting standards continues to limit the amount of useful quantitative information that can be extracted from peer-reviewed publications. Recommendations regarding reporting standards are considered, to enable such reviews to achieve more complete characterization of clinical outcomes. 1 Jackson A, Marks LB, Bentzen SM, Eisbruch A, Yorke ED, Ten Haken RK, Constine LS, Deasy JO. The lessons of QUANTEC: recommendations for reporting and gathering data on dose-volume dependencies of treatment outcome. Int J Radiat Oncol Biol Phys. 2010 Mar 1;76(3 Suppl):S155–60. Learning Objectives: Describe the techniques, types of cancer and dose schedules used in treating recurrent H&N cancers with SBRT List the radiobiological models that compete with the linear

  1. Designing the future: NBIC technologies and human performance enhancement.

    PubMed

    Canton, James

    2004-05-01

    Never before has any civilization had the unique opportunity to enhance human performance on the scale that we will face in the near future. The convergence of nanotechnology, biotechnology, information technology, and cognitive science (NBIC) is creating a set of powerful tools that have the potential to significantly enhance human performance as well as transform society, science, economics, and human evolution. As the NBIC convergence becomes more understood, the possibility that we may be able to enhance human performance in the three domains of therapy, augmentation, and designed evolution will become anticipated and even expected. In addition, NBIC convergence represents entirely new challenges for scientists, policymakers, and business leaders who will have, for the first time, vast new and powerful tools to shape markets, societies, and lifestyles. The emergence of NBIC convergence will challenge us in new ways to balance risk and return, threat and opportunity, and social responsibility and competitive advantage as we step into the 21st century.

  2. Enhanced thermoelectric performance of graphene nanoribbon-based devices

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hossain, Md Sharafat, E-mail: hossain@student.unimelb.edu.au; Huynh, Duc Hau; Nguyen, Phuong Duc

    There have been numerous theoretical studies on exciting thermoelectric properties of graphene nano-ribbons (GNRs); however, most of these studies are mainly based on simulations. In this work, we measure and characterize the thermoelectric properties of GNRs and compare the results with theoretical predictions. Our experimental results verify that nano-structuring and patterning graphene into nano-ribbons significantly enhance its thermoelectric power, confirming previous predictions. Although patterning results in lower conductance (G), the overall power factor (S{sup 2}G) increases for nanoribbons. We demonstrate that edge roughness plays an important role in achieving such an enhanced performance and support it through first principles simulations.more » We show that uncontrolled edge roughness, which is considered detrimental in GNR-based electronic devices, leads to enhanced thermoelectric performance of GNR-based thermoelectric devices. The result validates previously reported theoretical studies of GNRs and demonstrates the potential of GNRs for the realization of highly efficient thermoelectric devices.« less

  3. LETTER TO THE EDITOR: The second law of thermodynamics, TCP and Einstein causality in anti-de Sitter spacetime

    NASA Astrophysics Data System (ADS)

    Buchholz, Detlev; Florig, Martin; Summers, Stephen J.

    2000-01-01

    If the vacuum is passive for uniformly accelerated observers in anti-de Sitter spacetime (i.e. cannot be used by them to operate a perpetuum mobile ), they will (a) register a universal value of the Hawking-Unruh temperature, (b) discover a TCP symmetry and (c) find that observables in complementary wedge-shaped regions are commensurable (local) in the vacuum state. These results are model independent and hold in any theory which is compatible with some weak notion of spacetime localization.

  4. Enhanced osteogenesis of β-tricalcium phosphate reinforced silk fibroin scaffold for bone tissue biofabrication.

    PubMed

    Lee, Dae Hoon; Tripathy, Nirmalya; Shin, Jae Hun; Song, Jeong Eun; Cha, Jae Geun; Min, Kyung Dan; Park, Chan Hum; Khang, Gilson

    2017-02-01

    Scaffolds, used for tissue regeneration are important to preserve their function and morphology during tissue healing. Especially, scaffolds for bone tissue engineering should have high mechanical properties to endure load of bone. Silk fibroin (SF) from Bombyx mori silk cocoon has potency as a type of biomaterials in the tissue engineering. β-tricalcium phosphate (β-TCP) as a type of bioceramics is also critical as biomaterials for bone regeneration because of its biocompatibility, osteoconductivity, and mechanical strength. The aim of this study was to fabricate three-dimensional SF/β-TCP scaffolds and access its availability for bone grafts through in vitro and in vivo test. The scaffolds were fabricated in each different ratios of SF and β-TCP (100:0, 75:25, 50:50, 25:75). The characterizations of scaffolds were conducted by FT-IR, compressive strength, porosity, and SEM. The in vitro and in vivo tests were carried out by MTT, ALP, RT-PCR, SEM, μ-CT, and histological staining. We found that the SF/β-TCP scaffolds have high mechanical strength and appropriate porosity for bone tissue engineering. The study showed that SF/β-TCP (75:25) scaffold exhibited the highest osteogenesis compared with other scaffolds. The results suggested that SF/β-TCP (75:25) scaffold can be applied as one of potential bone grafts for bone tissue engineering. Copyright © 2016. Published by Elsevier B.V.

  5. Life context of pharmacological academic performance enhancement among university students--a qualitative approach.

    PubMed

    Hildt, Elisabeth; Lieb, Klaus; Franke, Andreas Günter

    2014-03-07

    Academic performance enhancement or cognitive enhancement (CE) via stimulant drug use has received increasing attention. The question remains, however, whether CE solely represents the use of drugs for achieving better academic or workplace results or whether CE also serves various other purposes. The aim of this study was to put the phenomenon of pharmacological academic performance enhancement via prescription and illicit (psycho-) stimulant use (Amphetamines, Methylphenidate) among university students into a broader context. Specifically, we wanted to further understand students' experiences, the effects of use on students and other factors, such as pressure to perform in their academic and private lives. A sample of 18 healthy university students reporting the non-medical use of prescription and illicit stimulants for academic performance enhancement was interviewed in a face-to-face setting. The leading questions were related to the situations and context in which the students considered the non-medical use of stimulants. Based on the resultant transcript, two independent raters identified six categories relating to the life context of stimulant use for academic performance enhancement: Context of stimulant use beyond academic performance enhancement, Subjective experience of enhancement, Timing of consumption, Objective academic results, Side effects, Pressure to perform. The answers reveal that academic performance enhancement through the use of stimulants is not an isolated phenomenon that solely aims at enhancing cognition to achieve better academic results but that the multifaceted life context in which it is embedded is of crucial relevance. The participants not only considered the stimulants advantageous for enhancing academic performance, but also for leading an active life with a suitable balance between studying and time off. The most common reasons given for stimulant use were to maximize time, to increase motivation and to cope with memorizing

  6. Transport Protocols for Wireless Mesh Networks

    NASA Astrophysics Data System (ADS)

    Eddie Law, K. L.

    Transmission control protocol (TCP) provides reliable connection-oriented services between any two end systems on the Internet. With TCP congestion control algorithm, multiple TCP connections can share network and link resources simultaneously. These TCP congestion control mechanisms have been operating effectively in wired networks. However, performance of TCP connections degrades rapidly in wireless and lossy networks. To sustain the throughput performance of TCP connections in wireless networks, design modifications may be required accordingly in the TCP flow control algorithm, and potentially, in association with other protocols in other layers for proper adaptations. In this chapter, we explain the limitations of the latest TCP congestion control algorithm, and then review some popular designs for TCP connections to operate effectively in wireless mesh network infrastructure.

  7. Enhanced thermoelectric performance of defected silicene nanoribbons

    NASA Astrophysics Data System (ADS)

    Zhao, W.; Guo, Z. X.; Zhang, Y.; Ding, J. W.; Zheng, X. J.

    2016-02-01

    Based on non-equilibrium Green's function method, we investigate the thermoelectric performance for both zigzag (ZSiNRs) and armchair (ASiNRs) silicene nanoribbons with central or edge defects. For perfect silicene nanoribbons (SiNRs), it is shown that with its width increasing, the maximum of ZT values (ZTM) decreases monotonously while the phononic thermal conductance increases linearly. For various types of edges and defects, with increasing defect numbers in longitudinal direction, ZTM increases monotonously while the phononic thermal conductance decreases. Comparing with ZSiNRs, defected ASiNRs possess higher thermoelectric performance due to higher Seebeck coefficient and lower thermal conductance. In particular, about 2.5 times enhancement to ZT values is obtained in ASiNRs with edge defects. Our theoretical simulations indicate that by controlling the type and number of defects, ZT values of SiNRs could be enhanced greatly which suggests their very appealing thermoelectric applications.

  8. Enhanced Performance of Streamline-Traced External-Compression Supersonic Inlets

    NASA Technical Reports Server (NTRS)

    Slater, John W.

    2015-01-01

    A computational design study was conducted to enhance the aerodynamic performance of streamline-traced, external-compression inlets for Mach 1.6. The current study explored a new parent flowfield for the streamline tracing and several variations of inlet design factors, including the axial displacement and angle of the subsonic cowl lip, the vertical placement of the engine axis, and the use of porous bleed in the subsonic diffuser. The performance was enhanced over that of an earlier streamline-traced inlet such as to increase the total pressure recovery and reduce total pressure distortion

  9. Calcium sources and their interaction with the different levels of non-phytate phosphorus affect performance and bone mineralization in broiler chickens.

    PubMed

    Hamdi, M; Solà-Oriol, D; Davin, R; Perez, J F

    2015-09-01

    An experiment was conducted to evaluate the influence of different Ca sources (limestone, Ca chloride, and Lipocal, a fat-encapsulated tricalcium phosphate, TCP) in conjunction with 4 dietary levels of non-phytate P (NPP) on performance, ileal digestibility of Ca and P, and bone mineralization in broiler chickens. Calcium sources were also evaluated in vitro to measure acid-binding capacity (ABC) and Ca solubility at different pH values. Ca chloride showed the highest solubility of Ca, with TCP showing the highest ABC. Ross male broiler-chicks were sorted by BW at 1 d post-hatch and assigned to 5 cages per diet with 5 birds per cage. Twelve diets were arranged in a 3×4 factorial of the 3 Ca sources and 4 levels of NPP (0.3%, 0.35%, 0.4% or 0.45%) consisting of 4 added P levels (Ca(H2PO4)2) with a high dose of phytase (1,150 U/kg) in all diets. On d 14 post-hatch, 3 birds were euthanized, and ileal digesta and the right tibia were collected to determine ileal Ca and P digestibility and bone mineralization, respectively. Feed intake (FI) and weight gain (WG) on d 14 was higher (P<0.01) with TCP and limestone than with Ca chloride. Added P increased the tibia weight and tibia ash content in chicks fed TCP up to 0.4% NPP and limestone up to 0.35% NPP. Calcium ileal digestibility was higher (P<0.01) with Ca chloride (73.7%) than with limestone (67.1%) or TCP (66.8%), which increased (P<0.05) with added levels of P from monocalcium phosphate. Phosphorus ileal digestibility was not affected by the Ca source and increased (P<0.001) with added levels of NPP. It can be concluded that starting broilers responded better to low-soluble Ca sources compared to high-soluble sources. A level of 0.35%-0.40% NPP with a high dose of phytase (1,150 U/kg) in diets including limestone or TCP is sufficient to guarantee performance and bone formation for broiler chickens from d 0 to d 14. © 2015 Poultry Science Association Inc.

  10. Medium-Term Function of a 3D Printed TCP/HA Structure as a New Osteoconductive Scaffold for Vertical Bone Augmentation: A Simulation by BMP-2 Activation

    PubMed Central

    Moussa, Mira; Carrel, Jean-Pierre; Scherrer, Susanne; Cattani-Lorente, Maria; Wiskott, Anselm; Durual, Stéphane

    2015-01-01

    Introduction: A 3D-printed construct made of orthogonally layered strands of tricalcium phosphate (TCP) and hydroxyapatite has recently become available. The material provides excellent osteoconductivity. We simulated a medium-term experiment in a sheep calvarial model by priming the blocks with BMP-2. Vertical bone growth/maturation and material resorption were evaluated. Materials and methods: Titanium hemispherical caps were filled with either bare- or BMP-2 primed constructs and placed onto the calvaria of adult sheep (n = 8). Histomorphometry was performed after 8 and 16 weeks. Results: After 8 weeks, relative to bare constructs, BMP-2 stimulation led to a two-fold increase in bone volume (Bare: 22% ± 2.1%; BMP-2 primed: 50% ± 3%) and a 3-fold decrease in substitute volume (Bare: 47% ± 5%; BMP-2 primed: 18% ± 2%). These rates were still observed at 16 weeks. The new bone grew and matured to a haversian-like structure while the substitute material resorbed via cell- and chemical-mediation. Conclusion: By priming the 3D construct with BMP-2, bone metabolism was physiologically accelerated, that is, enhancing vertical bone growth and maturation as well as material bioresorption. The scaffolding function of the block was maintained, leaving time for the bone to grow and mature to a haversian-like structure. In parallel, the material resorbed via cell-mediated and chemical processes. These promising results must be confirmed in clinical tests.

  11. Social psychological determinants of the use of performance-enhancing drugs by gym users.

    PubMed

    Wiefferink, C H; Detmar, S B; Coumans, B; Vogels, T; Paulussen, T G W

    2008-02-01

    The aim of this study is to identify the social psychological determinants of the use of performance-enhancing drugs by gym users who practice bodybuilding, fitness, powerlifting or combat sports. In this questionnaire-based study, 144 respondents answered questions on their actual use and intention to use such drugs and also on their background characteristics and beliefs, such as their attitudes, social influences and self-efficacy. While all social psychological determinants correlated with intention to use these drugs, the most important predictors were personal norms, beliefs about performance outcomes and the perceived behavior of others. Non-users held more restrictive norms about using performance-enhancing drugs, were less optimistic about the performance-enhancing outcomes and believed that fewer significant others used performance-enhancing drugs than users and ex-users. The results of this study indicate that users attribute advantages to performance-enhancing drugs and are inclined to overlook the risks of using them. Preventive interventions should focus on influencing personal norms and social processes.

  12. Rheological performance of bacterial cellulose based nonmineralized and mineralized hydrogel scaffolds

    NASA Astrophysics Data System (ADS)

    Basu, Probal; Saha, Nabanita; Bandyopadhyay, Smarak; Saha, Petr

    2017-05-01

    Bacterial cellulose (BC) based hydrogels (BC-PVP and BC-CMC) are modified with β-tri-calcium phosphate (β-TCP) and hydroxyapatite (HA) to improve the structural and functional properties of the existing hydrogel scaffolds. The modified hydrogels are then biomineralized with CaCO3 following liquid diffusion technique, where salt solutions of Na2CO3 (5.25 g/100 mL) and CaCl2 (7.35 g/100 mL) were involved. The BC-PVP and BC-CMC are being compared with the non-mineralized (BC-PVP-β-TCP/HA and BC-CMC-β-TCP/HA) and biomineralized (BC-PVP-β-TCP/HA-CaCO3 and BC-CMC-β-TCP/HA-CaCO3) hydrogels on the basis of their structural and rheological properties. The Fourier Transform Infrared (FTIR) spectral analysis demonstrated the presence of BC, CMC, PVP, β-TCP, HA in the non-mineralized and BC, CMC, PVP, β-TCP, HA and CaCO3 in the biomineralized samples. Interestingly, the morphological property of non-mineralized and biomineralized, hydrogels are different than that of BC-PVP and BC-CMC based novel biomaterials. The Scanning Electron Microscopic (SEM) images of the before mentioned samples reveal the denser structures than BC-PVP and BC-CMC, which exhibits the changes in their pore sizes. Concerning rheological analysis point of view, all the non-mineralized and biomineralized hydrogel scaffolds have shown significant elastic property. Additionally, the complex viscosity (η*) values have also found in decreasing order with the increase of angular frequency (ω) 0.1 rad.sec-1 to 100 rad.sec-1. All these BC based hydrogel scaffolds are elastic in nature, can be recommended for their application as an implant for bone tissue engineering.

  13. Mechanism of enhanced conversion of 1,2,3-trichloropropane by mutant haloalkane dehalogenase revealed by molecular modeling

    NASA Astrophysics Data System (ADS)

    Banáš, Pavel; Otyepka, Michal; Jeřábek, Petr; Petřek, Martin; Damborský, Jiří

    2006-06-01

    1,2,3-Trichloropropane (TCP) is a highly toxic, recalcitrant byproduct of epichlorohydrin manufacture. Haloalkane dehalogenase (DhaA) from Rhodococcus sp. hydrolyses the carbon-halogen bond in various halogenated compounds including TCP, but with low efficiency ( k cat/ K m = 36 s-1 M-1). A Cys176Tyr-DhaA mutant with a threefold higher catalytic efficiency for TCP dehalogenation has been previously obtained by error-prone PCR. We have used molecular simulations and quantum mechanical calculations to elucidate the molecular mechanisms involved in the improved catalysis of the mutant, and enantioselectivity of DhaA toward TCP. The Cys176Tyr mutation modifies the protein access and export routes. Substitution of the Cys residue by the bulkier Tyr narrows the upper tunnel, making the second tunnel "slot" the preferred route. TCP can adopt two major orientations in the DhaA enzyme, in one of which the halide-stabilizing residue Asn41 forms a hydrogen bond with the terminal halogen atom of the TCP molecule, while in the other it bonds with the central halogen atom. The differences in these binding patterns explain the preferential formation of the ( R)- over the ( S)-enantiomer of 2,3-dichloropropane-1-ol in the reaction catalyzed by the enzyme.

  14. Diagnostic performance of different measurement methods for lung nodule enhancement at quantitative contrast-enhanced computed tomography

    NASA Astrophysics Data System (ADS)

    Wormanns, Dag; Klotz, Ernst; Dregger, Uwe; Beyer, Florian; Heindel, Walter

    2004-05-01

    Lack of angiogenesis virtually excludes malignancy of a pulmonary nodule; assessment with quantitative contrast-enhanced CT (QECT) requires a reliable enhancement measurement technique. Diagnostic performance of different measurement methods in the distinction between malignant and benign nodules was evaluated. QECT (unenhanced scan and 4 post-contrast scans) was performed in 48 pulmonary nodules (12 malignant, 12 benign, 24 indeterminate). Nodule enhancement was the difference between the highest nodule density at any post-contrast scan and the unenhanced scan. Enhancement was determined with: A) the standard 2D method; B) a 3D method consisting of segmentation, removal of peripheral structures and density averaging. Enhancement curves were evaluated for their plausibility using a predefined set of criteria. Sensitivity and specificity were 100% and 33% for the 2D method resp. 92% and 55% for the 3D method using a threshold of 20 HU. One malignant nodule did not show significant enhancement with method B due to adjacent atelectasis which disappeared within the few minutes of the QECT examination. Better discrimination between benign and malignant lesions was achieved with a slightly higher threshold than proposed in the literature. Application of plausibility criteria to the enhancement curves rendered less plausibility faults with the 3D method. A new 3D method for analysis of QECT scans yielded less artefacts and better specificity in the discrimination between benign and malignant pulmonary nodules when using an appropriate enhancement threshold. Nevertheless, QECT results must be interpreted with care.

  15. High porous titanium scaffolds showed higher compatibility than lower porous beta-tricalcium phosphate scaffolds for regulating human osteoblast and osteoclast differentiation.

    PubMed

    Hirota, Makoto; Hayakawa, Tohru; Shima, Takaki; Ametani, Akihiro; Tohnai, Iwai

    2015-04-01

    We compared osteoblast and osteoclast differentiation when using beta-tricalcium phosphate (βTCP) and titanium scaffolds by investigating human mesenchymal stem cells (hMSCs) and osteoclast progenitor cell activities. hMSCs were cultured for 7, 14, and 21days on titanium scaffolds with 60%, 73%, and 87% porosity and on βTCP scaffolds with 60% and 75% porosity. Human osteoclast progenitor cells were cultured with osteoblast for 14 and 21days on 87% titanium and 75% βTCP scaffolds. Viable cell numbers with 60% and 73% titanium were higher than with 87% titanium and βTCP scaffolds (P<0.05). An 87% titanium scaffold resulted in the highest osteocalcin production with calcification on day 14 (P<0.01) in titanium scaffolds. All titanium scaffolds resulted in higher osteocalcin production on days 7 and 14 compared to βTCP scaffolds (P<0.01). Osteoblasts cultured on 87% titanium scaffolds suppressed osteoclast differentiation on day 7 but enhanced osteoclast differentiation on day 14 compared to 75% βTCP scaffolds (P<0.01). These findings concluded that high porosity titanium scaffolds could enhance progression of hMSC/osteoblast differentiation and regulated osteoclast differentiation cooperating with osteoblast differentiation for calcification as compared with lower porous βTCP. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Chiropractic treatment and the enhancement of sport performance: a narrative literature review

    PubMed Central

    Miners, Andrew L.

    2010-01-01

    A literature search and narrative review was carried out with the intent of determining the current level of knowledge regarding the chiropractic treatment of athletes for the purpose of sport performance enhancement. Of the fifty-nine relevant articles retrieved, only 7 articles of variable quality were obtained which specifically investigated/discussed chiropractic treatment and its involvement in sport performance enhancement. The role of the chiropractor in sport, unsubstantiated claims of performance enhancement, theories of how chiropractic treatment may influence sport performance, and the available evidence for the benefit of chiropractic treatment on sport performance are reviewed and discussed. Areas and directions for future studies are postulated. At this time there is insufficient evidence to convincingly support the notion that treatment provided by chiropractors can directly improve sport performance. PMID:21120012

  17. SrO- and MgO-doped microwave sintered 3D printed tricalcium phosphate scaffolds: mechanical properties and in vivo osteogenesis in a rabbit model.

    PubMed

    Tarafder, Solaiman; Dernell, William S; Bandyopadhyay, Amit; Bose, Susmita

    2015-04-01

    The presence of interconnected macro pores allows guided tissue regeneration in tissue engineering scaffolds. However, highly porous scaffolds suffer from having poor mechanical strength. Previously, we showed that microwave sintering could successfully be used to improve mechanical strength of macro porous tricalcium phosphate (TCP) scaffolds. This study reports the presence of SrO and MgO as dopants in TCP scaffolds improves mechanical and in vivo biological performance. We have used direct three dimensional printing (3DP) technology for scaffold fabrication. These 3DP scaffolds possessed multiscale porosity, that is, 3D interconnected designed macro pores along with intrinsic micro pores. A significant increase in mechanical strength, between 37 and 41%, was achieved due to SrO and MgO doping in TCP as compared with pure TCP. Maximum compressive strengths of 9.38 ± 1.86 MPa and 12.01 ± 1.56 MPa were achieved by conventional and microwave sintering, respectively, for SrO-MgO-doped 3DP scaffolds with 500 μm designed pores. Histomorphological and histomorphometric analysis revealed a significantly higher osteoid, bone and haversian canal formation induced by the presence of SrO and MgO dopants in 3DP TCP as compared with pure TCP scaffolds when tested in rabbit femoral condyle defect model. Increased osteon and thus enhanced network of blood vessel formation, and osteocalcin expression were observed in the doped TCP scaffolds. Our results show that these 3DP SrO-MgO-doped TCP scaffolds have the potential for early wound healing through accelerated osteogenesis and vasculogenesis. © 2014 Wiley Periodicals, Inc.

  18. Performance Comparison of SDN Solutions for Switching Dedicated Long-Haul Connections

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rao, Nageswara S

    2016-01-01

    We consider scenarios with two sites connected over a dedicated, long-haul connection that must quickly fail-over in response to degradations in host-to-host application performance. We present two methods for path fail-over using OpenFlowenabled switches: (a) a light-weight method that utilizes host scripts to monitor the application performance and dpctl API for switching, and (b) a generic method that uses two OpenDaylight (ODL) controllers and REST interfaces. The restoration dynamics of the application contain significant statistical variations due to the controllers, north interfaces and switches; in addition, the variety of vendor implementations further complicates the choice between different solutions. We presentmore » the impulse-response method to estimate the regressions of performance parameters, which enables a rigorous and objective comparison of different solutions. We describe testing results of the two methods, using TCP throughput and connection rtt as main parameters, over a testbed consisting of HP and Cisco switches connected over longhaul connections emulated in hardware by ANUE devices. The combination of analytical and experimental results demonstrates that dpctl method responds seconds faster than ODL method on average, while both methods restore TCP throughput.« less

  19. Life context of pharmacological academic performance enhancement among university students – a qualitative approach

    PubMed Central

    2014-01-01

    Background Academic performance enhancement or cognitive enhancement (CE) via stimulant drug use has received increasing attention. The question remains, however, whether CE solely represents the use of drugs for achieving better academic or workplace results or whether CE also serves various other purposes. The aim of this study was to put the phenomenon of pharmacological academic performance enhancement via prescription and illicit (psycho-) stimulant use (Amphetamines, Methylphenidate) among university students into a broader context. Specifically, we wanted to further understand students’ experiences, the effects of use on students and other factors, such as pressure to perform in their academic and private lives. Methods A sample of 18 healthy university students reporting the non-medical use of prescription and illicit stimulants for academic performance enhancement was interviewed in a face-to-face setting. The leading questions were related to the situations and context in which the students considered the non-medical use of stimulants. Results Based on the resultant transcript, two independent raters identified six categories relating to the life context of stimulant use for academic performance enhancement: Context of stimulant use beyond academic performance enhancement, Subjective experience of enhancement, Timing of consumption, Objective academic results, Side effects, Pressure to perform. Conclusions The answers reveal that academic performance enhancement through the use of stimulants is not an isolated phenomenon that solely aims at enhancing cognition to achieve better academic results but that the multifaceted life context in which it is embedded is of crucial relevance. The participants not only considered the stimulants advantageous for enhancing academic performance, but also for leading an active life with a suitable balance between studying and time off. The most common reasons given for stimulant use were to maximize time, to increase

  20. Optimizing the ASC WAN: evaluating network performance tools for comparing transport protocols.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lydick, Christopher L.

    2007-07-01

    The Advanced Simulation & Computing Wide Area Network (ASC WAN), which is a high delay-bandwidth network connection between US Department of Energy National Laboratories, is constantly being examined and evaluated for efficiency. One of the current transport-layer protocols which is used, TCP, was developed for traffic demands which are different from that on the ASC WAN. The Stream Control Transport Protocol (SCTP), on the other hand, has shown characteristics which make it more appealing to networks such as these. Most important, before considering a replacement for TCP on any network, a testing tool that performs well against certain criteria needsmore » to be found. In order to try to find such a tool, two popular networking tools (Netperf v.2.4.3 & v.2.4.6 (OpenSS7 STREAMS), and Iperf v.2.0.6) were tested. These tools implement both TCP and SCTP and were evaluated using four metrics: (1) How effectively can the tool reach a throughput near the bandwidth? (2) How much of the CPU does the tool utilize during operation? (3) Is the tool freely and widely available? And, (4) Is the tool actively developed? Following the analysis of those tools, this paper goes further into explaining some recommendations and ideas for future work.« less

  1. TCP J05074264+2447555 as a bright microlensing event due to a binary system with very low mass ratio component: hint for a new planetary system?

    NASA Astrophysics Data System (ADS)

    Nucita, A. A.; Licchelli, D.; De Paolis, F.; Ingrosso, G.; Strafella, F.

    2017-11-01

    The transient event labeled as TCP J05074264+2447555 (RA 05h07m42.64s, DEC +24°47'55.5" (J2000.0)) was first discovered by Kojima on UT 2017-10-25.688 in the Taurus region and suddenly recognized as something peculiar.

  2. Design of a Cognitive Tool to Enhance Problemsolving Performance

    ERIC Educational Resources Information Center

    Lee, Youngmin; Nelson, David

    2005-01-01

    The design of a cognitive tool to support problem-solving performance for external representation of knowledge is described. The limitations of conventional knowledge maps are analyzed in proposing the tool. The design principles and specifications are described. This tool is expected to enhance learners problem-solving performance by allowing…

  3. Conserved TCP domain of Sas-4/CPAP is essential for pericentriolar material tethering during centrosome biogenesis

    PubMed Central

    Zheng, Xiangdong; Gooi, Li Ming; Wason, Arpit; Gabriel, Elke; Mehrjardi, Narges Zare; Yang, Qian; Zhang, Xingrun; Debec, Alain; Basiri, Marcus L.; Avidor-Reiss, Tomer; Pozniakovsky, Andrei; Poser, Ina; Šarić, Tomo; Hyman, Anthony A.; Li, Haitao; Gopalakrishnan, Jay

    2014-01-01

    Pericentriolar material (PCM) recruitment to centrioles forms a key step in centrosome biogenesis. Deregulation of this process leads to centrosome aberrations causing disorders, one of which is autosomal recessive primary microcephaly (MCPH), a neurodevelopmental disorder where brain size is reduced. During PCM recruitment, the conserved centrosomal protein Sas-4/CPAP/MCPH6, known to play a role in centriole formation, acts as a scaffold for cytoplasmic PCM complexes to bind and then tethers them to centrioles to form functional centrosomes. To understand Sas-4’s tethering role, we determined the crystal structure of its T complex protein 10 (TCP) domain displaying a solvent-exposed single-layer of β-sheets fold. This unique feature of the TCP domain suggests that it could provide an “extended surface-like” platform to tether the Sas-4–PCM scaffold to a centriole. Functional studies in Drosophila, human cells, and human induced pluripotent stem cell-derived neural progenitor cells were used to test this hypothesis, where point mutations within the 9–10th β-strands (β9–10 mutants including a MCPH-associated mutation) perturbed PCM tethering while allowing Sas-4/CPAP to scaffold cytoplasmic PCM complexes. Specifically, the Sas-4 β9–10 mutants displayed perturbed interactions with Ana2, a centrosome duplication factor, and Bld-10, a centriole microtubule-binding protein, suggesting a role for the β9–10 surface in mediating protein–protein interactions for efficient Sas-4–PCM scaffold centriole tethering. Hence, we provide possible insights into how centrosomal protein defects result in human MCPH and how Sas-4 proteins act as a vehicle to tether PCM complexes to centrioles independent of its well-known role in centriole duplication. PMID:24385583

  4. The Development and Validation of a Rubric to Enhance Performer Feedback for Undergraduate Vocal Solo Performance

    ERIC Educational Resources Information Center

    Herrell, Katherine A.

    2014-01-01

    This is a study of the development and validation of a rubric to enhance performer feedback for undergraduate vocal solo performance. In the literature, assessment of vocal performance is under-represented, and the value of feedback from the assessment of musical performances, from the point of view of the performer, is nonexistent. The research…

  5. Microsphere-Based Scaffolds Encapsulating Tricalcium Phosphate And Hydroxyapatite For Bone Regeneration

    PubMed Central

    Gupta, Vineet; Lyne, Dina V.; Barragan, Marilyn; Berkland, Cory J.; Detamore, Michael S.

    2016-01-01

    Bioceramic mixtures of tricalcium phosphate (TCP) and hydroxyapatite (HAp) are widely used for bone regeneration because of their excellent cytocompatibility, osteoconduction, and osteoinduction. Therefore, we hypothesized that incorporation of a mixture of TCP and HAp in microsphere-based scaffolds would enhance osteogenesis of rat bone marrow stromal cells (rBMSCs) compared to a positive control of scaffolds with encapsulated bone-morphogenic protein-2 (BMP-2). Poly(D,L-lactic-co-glycolic acid) (PLGA) microsphere-based scaffolds encapsulating TCP and HAp mixtures in two different ratios (7:3 and 1:1) were fabricated with the same net ceramic content (30 wt%) to evaluate how incorporation of these ceramic mixtures would affect the osteogenesis in rBMSCs. Encapsulation of TCP/HAp mixtures impacted microsphere morphologies and the compressive moduli of the scaffolds. Additionally, TCP/HAp mixtures enhanced the end-point secretion of extracellular matrix (ECM) components relevant to bone tissue compared to the “blank” (PLGA-only) microsphere-based scaffolds as evidenced by the biochemical, gene expression, histology, and immunohistochemical characterization. Moreover, the TCP/HAp mixture groups even surpassed the BMP-2 positive control group in some instances in terms of matrix synthesis and gene expression. Lastly, gene expression data suggested that the rBMSCs responded differently to different TCP/HAp ratios presented to them. Altogether, it can be concluded that TCP/HAp mixtures stimulated the differentiation of rBMSCs toward an osteoblastic phenotype, and therefore may be beneficial in gradient microsphere-based scaffolds for osteochondral regeneration. PMID:27272903

  6. INT WFC pre-discovery detection of the nova M31N 2017-11a (AT2017hvi, PTSS-17zap, TCP J00425419+4130425)

    NASA Astrophysics Data System (ADS)

    Mantero-Castaneda, E. A.; Hernandez-Sanchez, M.; Arce-Tord, C.; Esteban-Gutierrez, A.; Garcia-Broock, E.; Garcia-Rivas, M.; Gonzalez-Cuesta, L.; Hermosa-Munoz, L.; Jimenez-Gallardo, A.; Lopez-Navas, E.; Otero-Santos, J.; Prendin, M. G.; Rodriguez-Sanchez, M.; Perez-Fournon, I.

    2017-12-01

    We report the pre-discovery detection of the nova M31N 2017-11a (AT2017hvi, PTSS-17zap, TCP J00425419+4130425) with the Isaac Newton Telescope* Wide Field Camera on the night of 29 October 2017, 4.845 days before the discovery observations on 2017/11/04.695 by the PMO-Tsinghua Supernova Survey (PTSS).

  7. TCP transcription factor, BRANCH ANGLE DEFECTIVE 1 (BAD1), is required for normal tassel branch angle formation in maize.

    PubMed

    Bai, Fang; Reinheimer, Renata; Durantini, Diego; Kellogg, Elizabeth A; Schmidt, Robert J

    2012-07-24

    In grass inflorescences, a structure called the "pulvinus" is found between the inflorescence main stem and lateral branches. The size of the pulvinus affects the angle of the lateral branches that emerge from the main axis and therefore has a large impact on inflorescence architecture. Through EMS mutagenesis we have identified three complementation groups of recessive mutants in maize having defects in pulvinus formation. All mutants showed extremely acute tassel branch angles accompanied by a significant reduction in the size of the pulvinus compared with normal plants. Two of the complementation groups correspond to mutations in the previously identified genes, RAMOSA2 (RA2) and LIGULELESS1 (LG1). Mutants corresponding to a third group were cloned using mapped-based approaches and found to encode a new member of the plant-specific TCP (TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL NUCLEAR ANTIGEN FACTOR) family of DNA-binding proteins, BRANCH ANGLE DEFECTIVE 1 (BAD1). BAD1 is expressed in the developing pulvinus as well as in other developing tissues, including the tassels and juvenile leaves. Both molecular and genetics studies show that RA2 is upstream of BAD1, whereas LG1 may function in a separate pathway. Our findings demonstrate that BAD1 is a TCP class II gene that functions to promote cell proliferation in a lateral organ, the pulvinus, and influences inflorescence architecture by impacting the angle of lateral branch emergence.

  8. Grade/Study-Performance Contracts, Enhanced Communication, Cooperative Learning, and Student Performance in Undergraduate Organic Chemistry.

    ERIC Educational Resources Information Center

    Dougherty, Ralph C.

    1997-01-01

    Describes and evaluates a teaching strategy, designed to increase student retention while maintaining academic performance levels in undergraduate organic chemistry, that uses grade/study-performance contracts, enhanced communication using electronic mail, and cooperative learning. Concludes that a series of interventions can substantially…

  9. Caffeine ingestion enhances Wingate performance: a meta-analysis.

    PubMed

    Grgic, Jozo

    2018-03-01

    The positive effects of caffeine ingestion on aerobic performance are well-established; however, recent findings are suggesting that caffeine ingestion might also enhance components of anaerobic performance. A commonly used test of anaerobic performance and power output is the 30-second Wingate test. Several studies explored the effects of caffeine ingestion on Wingate performance, with equivocal findings. To elucidate this topic, this paper aims to determine the effects of caffeine ingestion on Wingate performance using meta-analytic statistical techniques. Following a search through PubMed/MEDLINE, Scopus, and SportDiscus ® , 16 studies were found meeting the inclusion criteria (pooled number of participants = 246). Random-effects meta-analysis of standardized mean differences (SMD) for peak power output and mean power output was performed. Study quality was assessed using the modified version of the PEDro checklist. Results of the meta-analysis indicated a significant difference (p = .005) between the placebo and caffeine trials on mean power output with SMD values of small magnitude (0.18; 95% confidence interval: 0.05, 0.31; +3%). The meta-analysis performed for peak power output indicated a significant difference (p = .006) between the placebo and caffeine trials (SMD = 0.27; 95% confidence interval: 0.08, 0.47 [moderate magnitude]; +4%). The results from the PEDro checklist indicated that, in general, studies are of good and excellent methodological quality. This meta-analysis adds on to the current body of evidence showing that caffeine ingestion can also enhance components of anaerobic performance. The results presented herein may be helpful for developing more efficient evidence-based recommendations regarding caffeine supplementation.

  10. Bioactive and biodegradable silica biomaterial for bone regeneration.

    PubMed

    Wang, Shunfeng; Wang, Xiaohong; Draenert, Florian G; Albert, Olga; Schröder, Heinz C; Mailänder, Volker; Mitov, Gergo; Müller, Werner E G

    2014-10-01

    Biosilica, a biocompatible, natural inorganic polymer that is formed by an enzymatic, silicatein-mediated reaction in siliceous sponges to build up their inorganic skeleton, has been shown to be morphogenetically active and to induce mineralization of human osteoblast-like cells (SaOS-2) in vitro. In the present study, we prepared beads (microspheres) by encapsulation of β-tricalcium phosphate [β-TCP], either alone (control) or supplemented with silica or silicatein, into the biodegradable copolymer poly(d,l-lactide-co-glycolide) [PLGA]. Under the conditions used, ≈5% β-TCP, ≈9% silica, and 0.32μg/mg of silicatein were entrapped into the PLGA microspheres (diameter≈800μm). Determination of the biocompatibility of the β-TCP microspheres, supplemented with silica or silicatein, revealed no toxicity in the MTT based cell viability assay using SaOS-2 cells. The adherence of SaOS-2 cells to the surface of silica-containing microspheres was higher than for microspheres, containing only β-TCP. In addition, the silica-containing β-TCP microspheres and even more pronounced, a 1:1 mixture of microspheres containing β-TCP and silica, and β-TCP and silicatein, were found to strongly enhance the mineral deposition by SaOS-2 cells. Using these microspheres, first animal experiments with silica/biosilica were performed in female, adult New Zealand White rabbits to study the effect of the inorganic polymer on bone regeneration in vivo. The microspheres were implanted into 5mm thick holes, drilled into the femur of the animals, applying a bilateral comparison study design (3 test groups with 4-8 animals each). The control implant on one of the two hind legs contained microspheres with only β-TCP, while the test implant on the corresponding leg consisted either of microspheres containing β-TCP and silica, or a 1:1 mixture of microspheres, supplemented with β-TCP and silica, and β-TCP and silicatein. The results revealed that tissue/bone sections of silica

  11. Enhanced Motor Imagery-Based BCI Performance via Tactile Stimulation on Unilateral Hand.

    PubMed

    Shu, Xiaokang; Yao, Lin; Sheng, Xinjun; Zhang, Dingguo; Zhu, Xiangyang

    2017-01-01

    Brain-computer interface (BCI) has attracted great interests for its effectiveness in assisting disabled people. However, due to the poor BCI performance, this technique is still far from daily-life applications. One of critical issues confronting BCI research is how to enhance BCI performance. This study aimed at improving the motor imagery (MI) based BCI accuracy by integrating MI tasks with unilateral tactile stimulation (Uni-TS). The effects were tested on both healthy subjects and stroke patients in a controlled study. Twenty-two healthy subjects and four stroke patients were recruited and randomly divided into a control-group and an enhanced-group. In the control-group, subjects performed two blocks of conventional MI tasks (left hand vs. right hand), with 80 trials in each block. In the enhanced-group, subjects also performed two blocks of MI tasks, but constant tactile stimulation was applied on the non-dominant/paretic hand during MI tasks in the second block. We found the Uni-TS significantly enhanced the contralateral cortical activations during MI of the stimulated hand, whereas it had no influence on activation patterns during MI of the non-stimulated hand. The two-class BCI decoding accuracy was significantly increased from 72.5% (MI without Uni-TS) to 84.7% (MI with Uni-TS) in the enhanced-group ( p < 0.001, paired t -test). Moreover, stroke patients in the enhanced-group achieved an accuracy >80% during MI with Uni-TS. This novel approach complements the conventional methods for BCI enhancement without increasing source information or complexity of signal processing. This enhancement via Uni-TS may facilitate clinical applications of MI-BCI.

  12. Optical design applications for enhanced illumination performance

    NASA Astrophysics Data System (ADS)

    Gilray, Carl; Lewin, Ian

    1995-08-01

    Nonimaging optical design techniques have been applied in the illumination industry for many years. Recently however, powerful software has been developed which allows accurate simulation and optimization of illumination devices. Wide experience has been obtained in using such design techniques for practical situations. These include automotive lighting where safety is of greatest importance, commercial lighting systems designed for energy efficiency, and numerous specialized applications. This presentation will discuss the performance requirements of a variety of illumination devices. It will further cover design methodology and present a variety of examples of practical applications for enhanced system performance.

  13. Influence of Si substitution on the reactivity of α-tricalcium phosphate.

    PubMed

    Motisuke, Mariana; Mestres, Gemma; Renó, Caroline O; Carrodeguas, Raúl G; Zavaglia, Cecília A C; Ginebra, Maria-Pau

    2017-06-01

    Silicon substituted calcium phosphates have been widely studied over the last ten years due to their enhanced osteogenic properties. Notwithstanding, the role of silicon on α-TCP reactivity is not clear yet. Therefore, the aim of this work was to evaluate the reactivity and the properties of Si-α-TCP in comparison to α-TCP. Precursor powders have similar properties regarding purity, particle size distribution and specific surface area, which allowed a better comparison of the Si effects on their reactivity and cements properties. Both Si-α-TCP and α-TCP hydrolyzed to a calcium-deficient hydroxyapatite when mixed with water but their conversion rates were different. Si-α-TCP exhibited a slower setting rate than α-TCP, i.e. k SSA for Si-TCP (0.021g·m -2 ·h -1 ) was almost four times lower than for α-TCP (0.072g·m -2 ·h -1 ). On the other hand, the compressive strength of the CPC resulting from fully reacted Si-α-TCP was significantly higher (12.80±0.38MPa) than that of α-TCP (11.44±0.54MPa), due to the smaller size of the entangled precipitated apatite crystals. Copyright © 2017. Published by Elsevier B.V.

  14. Hyperbaric Oxygen Environment Can Enhance Brain Activity and Multitasking Performance

    PubMed Central

    Vadas, Dor; Kalichman, Leonid; Hadanny, Amir; Efrati, Shai

    2017-01-01

    Background: The Brain uses 20% of the total oxygen supply consumed by the entire body. Even though, <10% of the brain is active at any given time, it utilizes almost all the oxygen delivered. In order to perform complex tasks or more than one task (multitasking), the oxygen supply is shifted from one brain region to another, via blood perfusion modulation. The aim of the present study was to evaluate whether a hyperbaric oxygen (HBO) environment, with increased oxygen supply to the brain, will enhance the performance of complex and/or multiple activities. Methods: A prospective, double-blind randomized control, crossover trial including 22 healthy volunteers. Participants were asked to perform a cognitive task, a motor task and a simultaneous cognitive-motor task (multitasking). Participants were randomized to perform the tasks in two environments: (a) normobaric air (1 ATA 21% oxygen) (b) HBO (2 ATA 100% oxygen). Two weeks later participants were crossed to the alternative environment. Blinding of the normobaric environment was achieved in the same chamber with masks on while hyperbaric sensation was simulated by increasing pressure in the first minute and gradually decreasing to normobaric environment prior to tasks performance. Results: Compared to the performance at normobaric conditions, both cognitive and motor single tasks scores were significantly enhanced by HBO environment (p < 0.001 for both). Multitasking performance was also significantly enhanced in HBO environment (p = 0.006 for the cognitive part and p = 0.02 for the motor part). Conclusions: The improvement in performance of both single and multi-tasking while in an HBO environment supports the hypothesis which according to, oxygen is indeed a rate limiting factor for brain activity. Hyperbaric oxygenation can serve as an environment for brain performance. Further studies are needed to evaluate the optimal oxygen levels for maximal brain performance. PMID:29021747

  15. Hyperbaric Oxygen Environment Can Enhance Brain Activity and Multitasking Performance.

    PubMed

    Vadas, Dor; Kalichman, Leonid; Hadanny, Amir; Efrati, Shai

    2017-01-01

    Background: The Brain uses 20% of the total oxygen supply consumed by the entire body. Even though, <10% of the brain is active at any given time, it utilizes almost all the oxygen delivered. In order to perform complex tasks or more than one task (multitasking), the oxygen supply is shifted from one brain region to another, via blood perfusion modulation. The aim of the present study was to evaluate whether a hyperbaric oxygen (HBO) environment, with increased oxygen supply to the brain, will enhance the performance of complex and/or multiple activities. Methods: A prospective, double-blind randomized control, crossover trial including 22 healthy volunteers. Participants were asked to perform a cognitive task, a motor task and a simultaneous cognitive-motor task (multitasking). Participants were randomized to perform the tasks in two environments: (a) normobaric air (1 ATA 21% oxygen) (b) HBO (2 ATA 100% oxygen). Two weeks later participants were crossed to the alternative environment. Blinding of the normobaric environment was achieved in the same chamber with masks on while hyperbaric sensation was simulated by increasing pressure in the first minute and gradually decreasing to normobaric environment prior to tasks performance. Results: Compared to the performance at normobaric conditions, both cognitive and motor single tasks scores were significantly enhanced by HBO environment ( p < 0.001 for both). Multitasking performance was also significantly enhanced in HBO environment ( p = 0.006 for the cognitive part and p = 0.02 for the motor part). Conclusions: The improvement in performance of both single and multi-tasking while in an HBO environment supports the hypothesis which according to, oxygen is indeed a rate limiting factor for brain activity. Hyperbaric oxygenation can serve as an environment for brain performance. Further studies are needed to evaluate the optimal oxygen levels for maximal brain performance.

  16. Interference Drop Scheme: Enhancing QoS Provision in Multi-Hop Ad Hoc Networks

    NASA Astrophysics Data System (ADS)

    Luo, Chang-Yi; Komuro, Nobuyoshi; Takahashi, Kiyoshi; Kasai, Hiroyuki; Ueda, Hiromi; Tsuboi, Toshinori

    Ad hoc networking uses wireless technologies to construct networks with no physical infrastructure and so are expected to provide instant networking in areas such as disaster recovery sites and inter-vehicle communication. Unlike conventional wired networks services, services in ad hoc networks are easily disrupted by the frequent changes in traffic and topology. Therefore, solutions to assure the Quality of Services (QoS) in ad hoc networks are different from the conventional ones used in wired networks. In this paper, we propose a new queue management scheme, Interference Drop Scheme (IDS) for ad hoc networks. In the conventional queue management approaches such as FIFO (First-in First-out) and RED (Random Early Detection), a queue is usually managed by a queue length limit. FIFO discards packets according to the queue limit, and RED discards packets in an early and random fashion. IDS, on the other hand, manages the queue according to wireless interference time, which increases as the number of contentions in the MAC layer increases. When there are many MAC contentions, IDS discards TCP data packets. By observing the interference time and discarding TCP data packets, our simulation results show that IDS improves TCP performance and reduces QoS violations in UDP in ad hoc networks with chain, grid, and random topologies. Our simulation results also demonstrate that wireless interference time is a better metric than queue length limit for queue management in multi-hop ad hoc networks.

  17. δ-Similar Elimination to Enhance Search Performance of Multiobjective Evolutionary Algorithms

    NASA Astrophysics Data System (ADS)

    Aguirre, Hernán; Sato, Masahiko; Tanaka, Kiyoshi

    In this paper, we propose δ-similar elimination to improve the search performance of multiobjective evolutionary algorithms in combinatorial optimization problems. This method eliminates similar individuals in objective space to fairly distribute selection among the different regions of the instantaneous Pareto front. We investigate four eliminating methods analyzing their effects using NSGA-II. In addition, we compare the search performance of NSGA-II enhanced by our method and NSGA-II enhanced by controlled elitism.

  18. [Sports, use of performance enhancing drugs and addiction. A conceptual and epidemiological review].

    PubMed

    Franques, P; Auriacombe, M; Tignol, J

    2001-11-01

    Both the general public and non-sports medicine health professionals have recently been made aware of a large use of performance enhancing drugs among sports practicing subjects. It has been suggested that this behavior is similar to that of substance dependence. Also some have reported that practice of a sport could be in itself an addictive behavior. The main objective was to address the following question: is performance enhancing drug use in sports an addictive behavior? Methodology. We first reviewed the definition of performance enhancing drug use in sports and the diagnostic criteria of substance dependence as they are currently accepted and attempted to determine a possible common factor. Secondly we reviewed epidemiological data from the literature according to three approaches: Use of performance enhancing drugs is an important and increasing phenomenon among adolescents. It is sometimes associated to risk taking behaviors for health (syringe use and sharing). Competition participants are at increased risk (up to 20% according to some authors) and some substances (anabolic steroids) are also used by non-sports practicing individuals. It has not been shown that sports practicing subjects were more at risk of using addictive substances compared to non-sports practicing subjects. It is not established that practice of a sport is by itself a risk factor for substance use. However, it could be that a sub-group of individuals that practice certain types of sports in an intensive way, that use both performance enhancing drugs and addictive substances and that engage in health risk taking behaviors have an increased risk for developing a dependence syndrome to both addictive and performance enhancing drugs. This sub-group is even more at risk because some performance enhancing drugs (anabolic steroids) could increase the risk for occurrence of a substance dependence syndrome through neurobiological actions. Yet, the few available clinical studies show that at

  19. Priming of Spatial Distance Enhances Children's Creative Performance

    ERIC Educational Resources Information Center

    Liberman, Nira; Polack, Orli; Hameiri, Boaz; Blumenfeld, Maayan

    2012-01-01

    According to construal level theory, psychological distance promotes more abstract thought. Theories of creativity, in turn, suggest that abstract thought promotes creativity. Based on these lines of theorizing, we predicted that spatial distancing would enhance creative performance in elementary school children. To test this prediction, we primed…

  20. On implementation of DCTCP on three-tier and fat-tree data center network topologies.

    PubMed

    Zafar, Saima; Bashir, Abeer; Chaudhry, Shafique Ahmad

    2016-01-01

    A data center is a facility for housing computational and storage systems interconnected through a communication network called data center network (DCN). Due to a tremendous growth in the computational power, storage capacity and the number of inter-connected servers, the DCN faces challenges concerning efficiency, reliability and scalability. Although transmission control protocol (TCP) is a time-tested transport protocol in the Internet, DCN challenges such as inadequate buffer space in switches and bandwidth limitations have prompted the researchers to propose techniques to improve TCP performance or design new transport protocols for DCN. Data center TCP (DCTCP) emerge as one of the most promising solutions in this domain which employs the explicit congestion notification feature of TCP to enhance the TCP congestion control algorithm. While DCTCP has been analyzed for two-tier tree-based DCN topology for traffic between servers in the same rack which is common in cloud applications, it remains oblivious to the traffic patterns common in university and private enterprise networks which traverse the complete network interconnect spanning upper tier layers. We also recognize that DCTCP performance cannot remain unaffected by the underlying DCN architecture hence there is a need to test and compare DCTCP performance when implemented over diverse DCN architectures. Some of the most notable DCN architectures are the legacy three-tier, fat-tree, BCube, DCell, VL2, and CamCube. In this research, we simulate the two switch-centric DCN architectures; the widely deployed legacy three-tier architecture and the promising fat-tree architecture using network simulator and analyze the performance of DCTCP in terms of throughput and delay for realistic traffic patterns. We also examine how DCTCP prevents incast and outcast congestion when realistic DCN traffic patterns are employed in above mentioned topologies. Our results show that the underlying DCN architecture

  1. Attention distributed across sensory modalities enhances perceptual performance

    PubMed Central

    Mishra, Jyoti; Gazzaley, Adam

    2012-01-01

    This study investigated the interaction between top-down attentional control and multisensory processing in humans. Using semantically congruent and incongruent audiovisual stimulus streams, we found target detection to be consistently improved in the setting of distributed audiovisual attention versus focused visual attention. This performance benefit was manifested as faster reaction times for congruent audiovisual stimuli, and as accuracy improvements for incongruent stimuli, resulting in a resolution of stimulus interference. Electrophysiological recordings revealed that these behavioral enhancements were associated with reduced neural processing of both auditory and visual components of the audiovisual stimuli under distributed vs. focused visual attention. These neural changes were observed at early processing latencies, within 100–300 ms post-stimulus onset, and localized to auditory, visual, and polysensory temporal cortices. These results highlight a novel neural mechanism for top-down driven performance benefits via enhanced efficacy of sensory neural processing during distributed audiovisual attention relative to focused visual attention. PMID:22933811

  2. Doped tricalcium phosphate bone tissue engineering scaffolds using sucrose as template and microwave sintering: enhancement of mechanical and biological properties.

    PubMed

    Ke, Dongxu; Bose, Susmita

    2017-09-01

    β-tricalcium phosphate (β-TCP) is a widely used biocompatible ceramic in orthopedic and dental applications. However, its osteoinductivity and mechanical properties still require improvements. In this study, porous β-TCP and MgO/ZnO-TCP scaffolds were prepared by the thermal decomposition of sucrose. Crack-free cylindrical scaffolds could only be prepared with the addition of MgO and ZnO due to their stabilization effects. Porous MgO/ZnO-TCP scaffolds with a density of 61.39±0.66%, an estimated pore size of 200μm and a compressive strength of 24.96±3.07MPa were prepared by using 25wt% sucrose after conventional sintering at 1250°C. Microwave sintering further increased the compressive strength to 37.94±6.70MPa, but it decreased the open interconnected porosity to 8.74±1.38%. In addition, the incorporation of polycaprolactone (PCL) increased 22.36±3.22% of toughness while maintaining its compressive strength at 25.45±2.21MPa. Human osteoblast cell line was seeded on scaffolds to evaluate the effects of MgO/ZnO and PCL on the biological property of β-TCP in vitro. Both MgO/ZnO and PCL improved osteoinductivity of β-TCP. PCL also decreased osteoblastic apoptosis due to its particular surface chemistry. This novel porous MgO/ZnO-TCP scaffold with PCL shows improved mechanical and biological properties, which has great potential in bone tissue engineering applications. Copyright © 2017. Published by Elsevier B.V.

  3. Enhanced performance of a filter-sensor system.

    PubMed

    Sasaki, Isao; Josowicz, Mira; Janata, Jirí; Glezer, Ari

    2006-06-01

    In this paper are addressed two important, but seemingly unrelated issues: long term performance of a gas sensing array and performance of an air purification unit. It is shown that when considered together, the system can be regarded as a "smart filter". The enhancement is achieved by periodic differential sampling and measurement of the "upstream" and "downstream" gases of a filter. The correctly functioning filter supplies the "zero gas" from the downstream for the continuous sensor baseline correction. A key element in this scheme is the synthetic jet that delivers well-defined pulses of the two gases. The deterioration of the performance of the "smart filter" can be diagnosed from the response pattern of the sensor. The approach has been demonstrated on removal/sensing of ammonia gas from air.

  4. Maxillary sinus floor elevation using BMP-2 and Nell-1 gene-modified bone marrow stromal cells and TCP in rabbits.

    PubMed

    Xia, Lunguo; Xu, Yuanjin; Chang, Qing; Sun, Xiaojuan; Zeng, Deliang; Zhang, Wenjie; Zhang, Xiuli; Zhang, Zhiyuan; Jiang, Xinquan

    2011-07-01

    This study evaluated the synergistic osteogenic effect of bone morphogenetic protein-2 (BMP-2) and Nel-like molecule-1 (Nell-1) genes in a rabbit maxillary sinus floor elevation model. Bone marrow stromal cells (bMSCs) were cultured and transduced with AdEGFP, AdNell-1, AdBMP-2, or AdNell-1 + AdBMP-2 overexpression virus. These gene-modified autologous bMSCs were then combined with a β-tricalcium phosphate (β-TCP) granule scaffold and used to elevate the maxillary sinus floor in rabbits. bMSCs cotransduced with AdNell-1 + AdBMP-2 demonstrated a synergistic effect on osteogenic differentiation as detected by real-time PCR analysis on markers of runt-related transcription factor-2, osteocalcin, collagen type 1, alkaline phosphatase activity, and calcium deposits in vitro. As for maxillary sinus floor elevation in a rabbit model in vivo, AdNell-1 + AdBMP-2 gene-transduced autologeous bMSCs/β-TCP complex had the largest bone area and most mature bone structure among the groups, as detected by HE staining and immunohistochemistry at weeks 2 and 8 after implantation. Our data suggested that the BMP-2 and Nell-1 genes possessed a synergistic effect on osteogenic differentiation of bMSCs, while bMSCs modified with the BMP-2 and Nell-1 genes could promote new bone formation and maturation in the rabbit maxillary sinus model.

  5. WE-F-304-02: Recurrent HNC Treated with SBRT: TCP-Based Outcome Estimates

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Clump, D.

    Stereotactic Body Radiation Therapy (SBRT) was introduced clinically more than twenty years ago, and many subsequent publications have reported safety and efficacy data. The AAPM Working Group on Biological Effects of Hypofractionated Radiotherapy/SBRT (WGSBRT) extracted published treatment outcomes data from extensive literature searches to summarize and construct tumor control probability (TCP) and normal tissue complication probability (NTCP) models for six anatomical regions: Cranial, Head and Neck, Thoracic, Abdominal, Pelvic, and Spinal. In this session, we present the WGSBRT’s work for cranial sites, and recurrent head and neck cancer. From literature-based data and associated models, guidelines to aid with safe andmore » effective hypofractionated radiotherapy treatment are being determined. Further, the ability of existing and proposed radiobiological models to fit these data is considered as to the ability to distinguish between the linear-quadratic and alternative radiobiological models such as secondary cell death from vascular damage, immunogenic, or bystander effects. Where appropriate, specific model parameters are estimated. As described in “The lessons of QUANTEC,” (1), lack of adequate reporting standards continues to limit the amount of useful quantitative information that can be extracted from peer-reviewed publications. Recommendations regarding reporting standards are considered, to enable such reviews to achieve more complete characterization of clinical outcomes. 1 Jackson A, Marks LB, Bentzen SM, Eisbruch A, Yorke ED, Ten Haken RK, Constine LS, Deasy JO. The lessons of QUANTEC: recommendations for reporting and gathering data on dose-volume dependencies of treatment outcome. Int J Radiat Oncol Biol Phys. 2010 Mar 1;76(3 Suppl):S155–60. Learning Objectives: Describe the techniques, types of cancer and dose schedules used in treating recurrent H&N cancers with SBRT List the radiobiological models that compete with the linear

  6. Caries-Preventive Effect of NaF, NaF plus TCP, NaF plus CPP-ACP, and SDF Varnishes on Sound Dentin and Artificial Dentin Caries in vitro.

    PubMed

    Wierichs, Richard J; Stausberg, Sabrina; Lausch, Julian; Meyer-Lueckel, Hendrik; Esteves-Oliveira, Marcella

    2018-01-01

    The aim of this study was to compare the caries-preventive effect of different fluoride varnishes on sound dentin as well as on artificial dentin caries-like lesions. Bovine dentin specimens (n = 220) with one sound surface (ST) and one artificial caries lesion (DT) were prepared and randomly allocated to 11 groups. The interventions before pH cycling were as follows: application of a varnish containing NaF (22,600 ppm F-; Duraphat [NaF0/NaF1]), NaF plus tricalcium phosphate (22,600 ppm F-; Clinpro White Varnish Mint [TCP0/TCP1]), NaF plus casein phosphopeptide-stabilized amorphous calcium phosphate complexes (CPP-ACP; 22,600 ppm F-; MI Varnish [CPP0/CPP1]), or silver diamine fluoride (SDF; 35,400 ppm F-; Cariestop 30% [SDF0/SDF1]) and no intervention (NNB/N0/N1). During pH cycling (14 days, 6 × 120 min demineralization/day) half of the specimens in each group were brushed (10 s; 2 times/day) with either fluoride-free ("0"; e.g., TCP0) or 1,100 ppm F- ("1"; e.g., TCP1) dentifrice slurry. In another subgroup, the specimens were pH cycled but not brushed (NNB). Differences in integrated mineral loss (ΔΔZ), lesion depth (ΔLD), and colorimetric values (ΔΔE) were calculated between the values after initial demineralization and those after pH cycling, using transversal microradiography and photographic images. After pH cycling, no discoloration could be observed. Furthermore, NNB, N0, and N1 showed significantly increased ΔZDT/LDDT and ΔZST/LDST values, indicating further demineralization. In contrast, CPP0, CPP1, SDF0, and SDF1 showed significantly decreased ΔZDT/LDDT values, indicating remineralization (p ≤ 0.004; paired t test). CPP0, CPP1, SDF0, and SDF1 showed significantly higher changes in ΔΔZDT/ΔLDDT and ΔΔZST/ΔLDST than NNB, N0, and N1 (p < 0.001; Bonferroni post hoc test). In conclusion, under the conditions chosen, all fluoride varnishes prevented further demineralization. However, only NaF plus CPP-ACP and SDF could remineralize artificial

  7. Enhanced Performance of Streamline-Traced External-Compression Supersonic Inlets

    NASA Technical Reports Server (NTRS)

    Slater, John W.

    2015-01-01

    A computational design study was conducted to enhance the aerodynamic performance of streamline-traced, external-compression inlets for Mach 1.6. Compared to traditional external-compression, two-dimensional and axisymmetric inlets, streamline-traced inlets promise reduced cowl wave drag and sonic boom, but at the expense of reduced total pressure recovery and increased total pressure distortion. The current study explored a new parent flowfield for the streamline tracing and several variations of inlet design factors, including the axial displacement and angle of the subsonic cowl lip, the vertical placement of the engine axis, and the use of porous bleed in the subsonic diffuser. The performance was enhanced over that of an earlier streamline-traced inlet such as to increase the total pressure recovery and reduce total pressure distortion.

  8. Mechanisms for training security inspectors to enhance human performance

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Burkhalter, H.E.; Sessions, J.C.

    The Department of Energy (DOE) has established qualification standards for protective force personnel employed at nuclear facilities (10 CFR Part 1046 (Federal Register)). Training mechanisms used at Los Alamos to enhance human performance in meeting DOE standards include, but are not limited to, the following: for cardio-respiratory training, they utilize distance running, interval training, sprint training, pacing, indoor aerobics and circuit training; for muscular strength, free weights, weight machines, light hand weights, grip strength conditioners, and calistenics are employed; for muscular endurance, participants do high repetitions (15 - 40) using dumbbells, flex weights, resistive rubber bands, benches, and calisthenics; formore » flexibility, each training session devotes specific times to stretch the muscles involved for a particular activity. These training mechanisms with specific protocols can enhance human performance.« less

  9. Design and Demonstration of Emergency Control Modes for Enhanced Engine Performance

    NASA Technical Reports Server (NTRS)

    Liu, Yuan; Litt, Jonathan S.; Guo, Ten-Huei

    2013-01-01

    A design concept is presented for developing control modes that enhance aircraft engine performance during emergency flight scenarios. The benefits of increased engine performance to overall vehicle survivability during these situations may outweigh the accompanied elevated risk of engine failure. The objective involves building control logic that can consistently increase engine performance beyond designed maximum levels based on an allowable heightened probability of failure. This concept is applied to two previously developed control modes: an overthrust mode that increases maximum engine thrust output and a faster response mode that improves thrust response to dynamic throttle commands. This paper describes the redesign of these control modes and presents simulation results demonstrating both enhanced engine performance and robust maintenance of the desired elevated risk level.

  10. Enhancing health leadership performance using neurotherapy.

    PubMed

    Swingle, Paul G; Hartney, Elizabeth

    2018-05-01

    The discovery of neuroplasticity means the brain can change, functionally, in response to the environment and to learning. While individuals can develop harmful patterns of brain activity in response to stressors, they can also learn to modify or control neurological conditions associated with specific behaviors. Neurotherapy is one way of changing brain functioning to modify troubling conditions which can impair leadership performance, through responding to feedback on their own brain activity, and enhancing optimal leadership functioning through learning to maximize such cognitive strengths as mental efficiency, focus, creativity, perseverance, and executive functioning. The present article outlines the application of the concept of optimal performance training to organizational leadership in a healthcare context, by describing approaches to neurotherapy and illustrating their application through a case study of a health leader learning to overcome the neurological and emotional sequelae of workplace stress and trauma.

  11. Design of the NUSC (Naval Underwater System Center) Replacement TCP (transducer Calibration Platform) Mooring for Lake Seneca, Dresden, New York

    DTIC Science & Technology

    1983-05-01

    SMP has sinkers attached to wire rope within the water column. This location of sinkers was not duplicated on the TCP moor because of possible wear and...breaking (new chain) 1-3/4" wire rope breaking strength is approx. 224. kips; F.S. = 6.4 against breaking (new rope) Buoy, dia=9.5’,h=5’ buoy freeboard is...6.4 against breakingconnecting agis 1-3/4" wire rope with J b- chain tails 13 See Appendix B for details of the mooring buoy design and Appendix C

  12. EKF-Based Enhanced Performance Controller Design for Nonlinear Stochastic Systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhou, Yuyang; Zhang, Qichun; Wang, Hong

    In this paper, a novel control algorithm is presented to enhance the performance of tracking property for a class of non-linear dynamic stochastic systems with unmeasurable variables. To minimize the entropy of tracking errors without changing the existing closed loop with PI controller, the enhanced performance loop is constructed based on the state estimation by extended Kalman Filter and the new controller is designed by full state feedback following this presented control algorithm. Besides, the conditions are obtained for the stability analysis in the mean square sense. In the end, the comparative simulation results are given to illustrate the effectivenessmore » of proposed control algorithm.« less

  13. Constitutive Expression of a miR319 Gene Alters Plant Development and Enhances Salt and Drought Tolerance in Transgenic Creeping Bentgrass1[W][OA

    PubMed Central

    Zhou, Man; Li, Dayong; Li, Zhigang; Hu, Qian; Yang, Chunhua; Zhu, Lihuang; Luo, Hong

    2013-01-01

    MicroRNA319 (miR319) is one of the first characterized and conserved microRNA families in plants and has been demonstrated to target TCP (for TEOSINTE BRANCHED/CYCLOIDEA/PROLIFERATING CELL FACTORS [PCF]) genes encoding plant-specific transcription factors. MiR319 expression is regulated by environmental stimuli, suggesting its involvement in plant stress response, although experimental evidence is lacking and the underlying mechanism remains elusive. This study investigates the role that miR319 plays in the plant response to abiotic stress using transgenic creeping bentgrass (Agrostis stolonifera) overexpressing a rice (Oryza sativa) miR319 gene, Osa-miR319a. We found that transgenic plants overexpressing Osa-miR319a displayed morphological changes and exhibited enhanced drought and salt tolerance associated with increased leaf wax content and water retention but reduced sodium uptake. Gene expression analysis indicated that at least four putative miR319 target genes, AsPCF5, AsPCF6, AsPCF8, and AsTCP14, and a homolog of the rice NAC domain gene AsNAC60 were down-regulated in transgenic plants. Our results demonstrate that miR319 controls plant responses to drought and salinity stress. The enhanced abiotic stress tolerance in transgenic plants is related to significant down-regulation of miR319 target genes, implying their potential for use in the development of novel molecular strategies to genetically engineer crop species for enhanced resistance to environmental stress. PMID:23292790

  14. Performance enhancement in a semi-autonomous confined microsociety

    NASA Technical Reports Server (NTRS)

    Brady, J. V.; Bernstein, D. J.; Foltin, R. W.; Nellis, M. J.

    1988-01-01

    Research in a continuously programmed human experimental laboratory has been directed toward identifying, defining, and expanding generalized knowledge concerning motivational factors within the structure of human behavioral repertoires that maintain and enhance performance. Participants (in groups of three) engaged in a series of repetitive work activities (e.g., word sorting and rug-hooking) for extended periods each day, while living continuously in a residential laboratory. Other parts of the day were spent either interacting socially with other participants or engaging in individual recreational activities. The percentage of time devoted to the various work tasks provided the basis for selecting one activity that occurred with high frequency and one with low frequency. Performance of the low-frequency activity was then required in order to gain access to the high-frequency activity. Under such contingencies, time devoted to the original low-frequency activity increased greatly, and the participants consistently did more than the required amount of the low-frequency work than was necessary to restore access to the restricted work activity. The theoretical significance of these findings resides in the clear demonstration that a time-based model of value applies as well to the enhancement of work-like performance as it does to voluntarily selected or preferred recreational activities.

  15. The Future of Performance-Enhancing Substances in Sport.

    ERIC Educational Resources Information Center

    Bahrke, Michael S.; Yesalis, Charles E.

    2002-01-01

    Discusses the use of performance-enhancing substances in athletics, focusing on the use-detection race, burgeoning new products and off-label uses, and ways to combat the problem. The article suggests drug education programs, particularly those for adolescent athletes, have the potential to change behavior and be more cost-effective than further…

  16. Technology in Paralympic sport: performance enhancement or essential for performance?

    PubMed

    Burkett, Brendan

    2010-02-01

    People with disabilities often depend on assistive devices to enable activities of daily living as well as to compete in sport. Technological developments in sport can be controversial. To review, identify and describe current technological developments in assistive devices used in the summer Paralympic Games; and to prepare for the London 2012 Games, the future challenges and the role of technology are debated. A systematic review of the peer-reviewed literature and personal observations of technological developments at the Athens (2004) and Beijing (2008) Paralympic Games was conducted. Standard assistive devices can inhibit the Paralympians' abilities to perform the strenuous activities of their sports. Although many Paralympic sports only require technology similar to their Olympic counterparts, several unique technological modifications have been made in prosthetic and wheelchair devices. Technology is essential for the Paralympic athlete, and the potential technological advantage for a Paralympian, when competing against an Olympian, is unclear. Technology must match the individual requirements of the athlete with the sport in order for Paralympians to safely maximise their performance. Within the 'performance enhancement or essential for performance?' debate, any potential increase in mechanical performance from an assistive device must be considered holistically with the compensatory consequences the disability creates. To avoid potential technology controversies at the 2012 London Olympic and Paralympic Games, the role of technology in sport must be clarified.

  17. Assessment of mass detection performance in contrast enhanced digital mammography

    NASA Astrophysics Data System (ADS)

    Carton, Ann-Katherine; de Carvalho, Pablo M.; Li, Zhijin; Dromain, Clarisse; Muller, Serge

    2015-03-01

    We address the detectability of contrast-agent enhancing masses for contrast-agent enhanced spectral mammography (CESM), a dual-energy technique providing functional projection images of breast tissue perfusion and vascularity using simulated CESM images. First, the realism of simulated CESM images from anthropomorphic breast software phantoms generated with a software X-ray imaging platform was validated. Breast texture was characterized by power-law coefficients calculated in data sets of real clinical and simulated images. We also performed a 2-alternative forced choice (2-AFC) psychophysical experiment whereby simulated and real images were presented side-by-side to an experienced radiologist to test if real images could be distinguished from the simulated images. It was found that texture in our simulated CESM images has a fairly realistic appearance. Next, the relative performance of human readers and previously developed mathematical observers was assessed for the detection of iodine-enhancing mass lesions containing different contrast agent concentrations. A four alternative-forced-choice (4 AFC) task was designed; the task for the model and human observer was to detect which one of the four simulated DE recombined images contained an iodineenhancing mass. Our results showed that the NPW and NPWE models largely outperform human performance. After introduction of an internal noise component, both observers approached human performance. The CHO observer performs slightly worse than the average human observer. There is still work to be done in improving model observers as predictors of human-observer performance. Larger trials could also improve our test statistics. We hope that in the future, this framework of software breast phantoms, virtual image acquisition and processing, and mathematical observers can be beneficial to optimize CESM imaging techniques.

  18. Assessment and quantification of patient set-up errors in nasopharyngeal cancer patients and their biological and dosimetric impact in terms of generalized equivalent uniform dose (gEUD), tumour control probability (TCP) and normal tissue complication probability (NTCP).

    PubMed

    Boughalia, A; Marcie, S; Fellah, M; Chami, S; Mekki, F

    2015-06-01

    The aim of this study is to assess and quantify patients' set-up errors using an electronic portal imaging device and to evaluate their dosimetric and biological impact in terms of generalized equivalent uniform dose (gEUD) on predictive models, such as the tumour control probability (TCP) and the normal tissue complication probability (NTCP). 20 patients treated for nasopharyngeal cancer were enrolled in the radiotherapy-oncology department of HCA. Systematic and random errors were quantified. The dosimetric and biological impact of these set-up errors on the target volume and the organ at risk (OARs) coverage were assessed using calculation of dose-volume histogram, gEUD, TCP and NTCP. For this purpose, an in-house software was developed and used. The standard deviations (1SDs) of the systematic set-up and random set-up errors were calculated for the lateral and subclavicular fields and gave the following results: ∑ = 0.63 ± (0.42) mm and σ = 3.75 ± (0.79) mm, respectively. Thus a planning organ at risk volume (PRV) margin of 3 mm was defined around the OARs, and a 5-mm margin used around the clinical target volume. The gEUD, TCP and NTCP calculations obtained with and without set-up errors have shown increased values for tumour, where ΔgEUD (tumour) = 1.94% Gy (p = 0.00721) and ΔTCP = 2.03%. The toxicity of OARs was quantified using gEUD and NTCP. The values of ΔgEUD (OARs) vary from 0.78% to 5.95% in the case of the brainstem and the optic chiasm, respectively. The corresponding ΔNTCP varies from 0.15% to 0.53%, respectively. The quantification of set-up errors has a dosimetric and biological impact on the tumour and on the OARs. The developed in-house software using the concept of gEUD, TCP and NTCP biological models has been successfully used in this study. It can be used also to optimize the treatment plan established for our patients. The gEUD, TCP and NTCP may be more suitable tools to assess the treatment plans

  19. The Performance Blueprint: An Integrated Logic Model Developed To Enhance Performance Measurement Literacy: The Case of Performance-Based Contract Management.

    ERIC Educational Resources Information Center

    Longo, Paul J.

    This study explored the mechanics of using an enhanced, comprehensive multipurpose logic model, the Performance Blueprint, as a means of building evaluation capacity, referred to in this paper as performance measurement literacy, to facilitate the attainment of both service-delivery oriented and community-oriented outcomes. The application of this…

  20. Chlorella vulgaris cultivation in sludge extracts from 2,4,6-TCP wastewater treatment for toxicity removal and utilization.

    PubMed

    Wang, Lu; Chen, Xiurong; Wang, Hualin; Zhang, Yuying; Tang, Qingjie; Li, Jiahui

    2017-02-01

    Chlorella vulgaris was cultivated in different proportions of activated sludge extracts, which was from the treatment of the synthetic wastewater containing 2,4,6-trichlorophenol (2,4,6-TCP). The nutrients, total nitrogen (TN) and total phosphorus (TP), were removed over 45% and 90%, respectively. The maximum reduction amount of ecotoxicity and total organic carbon (TOC) occurred in the 100% sludge group on the 8th day (68%; 86.2 mg L -1 ). The variations of Excitation-emission matrix spectra (EEMs) and TOC indicated that extracellular organic matters (EOM) produced by algae led to TOC increase in the medium. The cell density was close to each other for groups with sludge extract proportion below 50%; sludge extracts (below 75% addition) had a stimulating effect on the accumulation of chlorophyll-a in per unit algal cell. Superoxide dismutase (SOD) variation demonstrated that C. vulgaris response positively to sludge extracts addition. Lipid content in C. vulgaris was up to its maximum value on the 8th day. Considering the performance on nutrients removal, toxicity reduction and algal growth, the optimal cultivation period for C. vulgaris before harvesting was around 8 days with sludge extracts proportion below 50%. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Physicomechanical, In Vitro and In Vivo Performance of 3D Printed Doped Tricalcium Phosphate Scaffolds for Bone Tissue Engineering and Drug Delivery

    NASA Astrophysics Data System (ADS)

    Tarafder, Solaiman

    Although tricalcium phosphate (TCP) is widely used in bone tissue engineering, the strength degradation kinetics is not well controlled. This study focuses on the underlying mechanism of strength degradation kinetics by incorporating trace elements in TCP. The objective of this research is to modify the mechanical properties of TCP to achieve the desired degradation rate for the specific need, and improve the in vivo bioactivity for early wound healing by incorporating trace elements such as strontium (Sr2+), magnesium (Mg2+) and silicon (Si4+) as dopants. The hypothesis of this research is that the presence of different trace elements in TCP will influence its phase stability, microstructure, mechanical strength, and both in vitro and in vivo bioactivity. Direct three dimensional printing (3DP) was used to fabricate designed interconnected macroporous pure and doped TCP scaffolds. Microwave sintering as opposed to conventional sintering was also used for better densification and higher mechanical strength. A maximum compressive strength of 10.95 +/- 1.28 MPa and 12.01 +/- 1.56 MPa were achieved for pure and Sr2+-Mg2+ doped TCP scaffolds with 500 microm designed pores (˜400 microm after sintering) sintered in microwave furnace, respectively. Substitution of Mg2+ and Sr2+ into calcium (Ca2+) sites of TCP crystal lattice contributed to phase stability and controlled gradual degradation. On the other hand, Si4+ substitution into phosphorous (P5+) sites destabilized the crystal structure and accelerated degradation of TCP. Interconnected macroporous beta-TCP scaffolds facilitated in vivo guided bone tissue regeneration through infiltration of cells and extracellular matrix into the designed pores. Presence of Sr2+, Mg2+ and Si4+ into beta-TCP induced increased in vivo early bone formation and better bone remodeling through increased extracellular matrix production such as, collagen and osteocalcin, when tested in rat and rabbit distal femur model. The presence of Si4

  2. In vitro degradation and cell response of calcium carbonate composite ceramic in comparison with other synthetic bone substitute materials.

    PubMed

    He, Fupo; Zhang, Jing; Yang, Fanwen; Zhu, Jixiang; Tian, Xiumei; Chen, Xiaoming

    2015-05-01

    The robust calcium carbonate composite ceramics (CC/PG) can be acquired by fast sintering calcium carbonate at a low temperature (650 °C) using a biocompatible, degradable phosphate-based glass (PG) as sintering agent. In the present study, the in vitro degradation and cell response of CC/PG were assessed and compared with 4 synthetic bone substitute materials, calcium carbonate ceramic (CC), PG, hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) ceramics. The degradation rates in decreasing order were as follows: PG, CC, CC/PG, β-TCP, and HA. The proliferation of rat bone mesenchymal stem cells (rMSCs) cultured on the CC/PG was comparable with that on CC and PG, but inferior to HA and β-TCP. The alkaline phosphatase (ALP) activity of rMSCs on CC/PG was lower than PG, comparable with β-TCP, but higher than HA. The rMSCs on CC/PG and PG had enhanced gene expression in specific osteogenic markers, respectively. Compared to HA and β-TCP, the rMSCs on the CC/PG expressed relatively lower level of collagen I and runt-related transcription factor 2, but showed more considerable expression of osteopontin. Although CC, PG, HA, and β-TCP possessed impressive performances in some specific aspects, they faced extant intrinsic drawbacks in either degradation rate or mechanical strength. Based on considerable compressive strength, moderate degradation rate, good cell response, and being free of obvious shortcoming, the CC/PG is promising as another choice for bone substitute materials. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Protocol Support for a New Satellite-Based Airspace Communication Network

    NASA Technical Reports Server (NTRS)

    Shang, Yadong; Hadjitheodosiou, Michael; Baras, John

    2004-01-01

    We recommend suitable transport protocols for an aeronautical network supporting Internet and data services via satellite. We study the characteristics of an aeronautical satellite hybrid network and focus on the problems that cause dramatically degraded performance of the Transport Protocol. We discuss various extensions to standard TCP that alleviate some of these performance problems. Through simulation, we identify those TCP implementations that can be expected to perform well. Based on the observation that it is difficult for an end-to-end solution to solve these problems effectively, we propose a new TCP-splitting protocol, termed Aeronautical Transport Control Protocol (AeroTCP). The main idea of this protocol is to use a fixed window for flow control and one duplicated acknowledgement (ACK) for fast recovery. Our simulation results show that AeroTCP can maintain higher utilization for the satellite link than end-to-end TCP, especially in high BER environment.

  4. Psychoactive drug consumption: performance-enhancing behaviour and pharmacodependence in workers.

    PubMed

    Ngoundo-Mbongue, T B; Niezborala, M; Sulem, P; Briant-Vincens, D; Bancarel, Y; Jansou, P; Chastan, E; Montastruc, J L; Lapeyre-Mestre, M

    2005-02-01

    The aim of this study was to investigate factors associated to psychoactive medication use and dependence in working environment during a 1-year period. We performed a 1-year-follow-up cohort study including workers from Toulouse metropolitan area. During their annual compulsory examination to assess their aptitude to work, subjects were asked to fill in an anonymous questionnaire at 1 year interval, in May 2000 and May-June 2001. Among a study sample of 1273 subjects (47.4% of men, mean age 39.2 +/- 9.2 years), the prevalence of psychoactive medication use at baseline was 9.1% (4.3% anxiolytic, 1.9% hypnotic, 1.7% antidepressant, 2.1% opiate analgesic and 0.5% antipsychotic drugs, according to ATC classification). Dependence on these drugs was found in 3.5% of workers. This consumption was associated with professional categories (higher in employees versus senior executive, Odds Ratio: 1.80; 95% Confidence Interval [1.04-3.11]), low job satisfaction and outside workplace (1.92; [1.30-2.84] and 3.40; [2.27-5.09] respectively), and patterns of medication use at workplace: for sleeping disorders related to job (18.27; [11.81-28.26]), for enhancing performance at work (28.13; [12.00-65.92]), for relieving unpleasant symptoms at work (22.98; [9.59-55.01]). The risk of psychoactive medication chronic use (psychoactive drug users in 2000 and 2001), and dependence at 1 year were both strongly associated with nicotine dependence (5.99 and 6.23, respectively) and performance-enhancing behaviour with drugs and/or alcohol (8.35 and 3.32 respectively), whereas current use (psychoactive drug users only in 2001) was strongly associated with performance-enhancing behaviour. Among workers using psychoactive drugs, one out of three are dependent on psychoactive medications. Performance-enhancing behaviour and coping strategies might be a determinant of psychoactive drug use and could lead to dependence in the workplace.

  5. Drink Availability is Associated with Enhanced Examination Performance in Adults

    ERIC Educational Resources Information Center

    Pawson, Chris; Gardner, Mark R.; Doherty, Sarah; Martin, Laura; Soares, Rute; Edmonds, Caroline J.

    2013-01-01

    While dehydration has negative effects on memory and attention, few studies have investigated whether drinking water can enhance cognitive performance, and none have addressed this in a real-world setting. In this study we explored the potential benefits of the availability of water for undergraduates. The exam performance of students who brought…

  6. Chaperonin Containing-TCP-1 Protein Level in Breast Cancer Cells Predicts Therapeutic Application of a Cytotoxic Peptide

    PubMed Central

    Bassiouni, Rania; Nemec, Kathleen; Iketani, Ashley; Flores, Orielyz; Showalter, Anne; Khaled, Amr S.; Vishnubhotla, Priya; Sprung, Robert W.; Kaittanis, Charalambos; Perez, Jesus M.; Khaled, Annette R.

    2016-01-01

    Purpose Metastatic disease is a leading cause of death for patients with breast cancer, driving the need for new therapies. CT20p is a peptide previously discovered by our group that displays cancer-specific cytotoxicity. To design the optimal therapeutic use of the peptide, we identified the intracellular target of CT20p in breast cancer cells, correlating expression patterns of the target with susceptibility to CT20p. Experimental Design Using polymeric nanoparticles to deliver CT20p, we assessed cytoskeletal changes, cell migration, adhesion, and viability in cells treated with the peptide. Protein pull-down experiments, coupled to mass spectrometry, enabled identification of the peptide’s intracellular target. Biochemical and histological techniques validated target identity in human cell lines and breast cancer tissue microarrays and revealed susceptibility patterns to CT20p. Results Chaperonin Containing TCP-1 (CCT) was identified as the intracellular target of CT20p. Cancer cells susceptible to CT20p had increased CCT, and overexpression of CCTβ, a subunit of the CCT complex, enhanced susceptibility to CT20p. Susceptible cells displayed reduced tubulin, a substrate of CCT, and inhibition of migration upon CT20p treatment. CCTβ levels were higher in invasive ductal carcinomas than in cancer adjacent tissues and increased with breast cancer stage. Decreased breast cancer patient survival correlated with genomic alternations in CCTβ and higher levels of the chaperone. Conclusion Increased CCT protein in breast cancer cells underlies the cytotoxicity of CT20p. CCT is thus a potential target for therapeutic intervention and serves as a companion diagnostic to personalize the therapeutic use of CT20p for breast cancer treatment. PMID:27012814

  7. Enhancement of SOFC Cathode Electrochemical Performance Using Multi-Phase Interfaces

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Morgan, Dane

    2015-09-30

    This work explored the use of oxide heterostructures for enhancing the catalytic and degradation properties of solid oxide fuel cell (SOFC) cathode electrodes. We focused on heterostructures of Ruddlesden-Popper and perovskite phases. Building on previous work showing enhancement of the Ruddlesden-Popper (La,Sr) 2CoO 4 / perovskite (La,Sr)CoO 3 heterostructure compared to pure (La,Sr)CoO 3 we explored the application of related heterostructures of Ruddlesden-Popper phases on perovskite (La,Sr)(Co,Fe)O 3. Our approaches included thin-film electrodes, physical and electrochemical characterization, elementary reaction kinetics modeling, and ab initio simulations. We demonstrated that Sr segregation to surfaces is likely playing a critical role in themore » performance of (La,Sr)CoO 3 and (La,Sr)(Co,Fe)O 3 and that modification of this Sr segregation may be the mechanism by which Ruddlesden-Popper coatings enhance performances. We determined that (La,Sr)(Co,Fe)O 3 could be enhanced in thin films by about 10× by forming a heterostructure simultaneously with (La,Sr) 2CoO 4 and (La,Sr)CoO 3. We hope that future work will develop this heterostructure for use as a bulk porous electrode.« less

  8. Review of Literature: Utilizing Film/Videotape through Modeling or Self Examination of Performance To Enhance Performance.

    ERIC Educational Resources Information Center

    Mills, Brett D.

    This paper examines eight studies that utilized film or videotape to enhance motor performance through modeling or self-examination of performance. The studies, dating as far back as 1944, dealt with learning bowling, golf, basketball, throwing, gymnastics, racquetball, and other motor tasks. For each study, the paper outlines the problem, the…

  9. Mesoporous bioactive glass nanolayer-functionalized 3D-printed scaffolds for accelerating osteogenesis and angiogenesis

    NASA Astrophysics Data System (ADS)

    Zhang, Yali; Xia, Lunguo; Zhai, Dong; Shi, Mengchao; Luo, Yongxiang; Feng, Chun; Fang, Bing; Yin, Jingbo; Chang, Jiang; Wu, Chengtie

    2015-11-01

    The hierarchical microstructure, surface and interface of biomaterials are important factors influencing their bioactivity. Porous bioceramic scaffolds have been widely used for bone tissue engineering by optimizing their chemical composition and large-pore structure. However, the surface and interface of struts in bioceramic scaffolds are often ignored. The aim of this study is to incorporate hierarchical pores and bioactive components into the bioceramic scaffolds by constructing nanopores and bioactive elements on the struts of scaffolds and further improve their bone-forming activity. Mesoporous bioactive glass (MBG) modified β-tricalcium phosphate (MBG-β-TCP) scaffolds with a hierarchical pore structure and a functional strut surface (~100 nm of MBG nanolayer) were successfully prepared via 3D printing and spin coating. The compressive strength and apatite-mineralization ability of MBG-β-TCP scaffolds were significantly enhanced as compared to β-TCP scaffolds without the MBG nanolayer. The attachment, viability, alkaline phosphatase (ALP) activity, osteogenic gene expression (Runx2, BMP2, OPN and Col I) and protein expression (OPN, Col I, VEGF, HIF-1α) of rabbit bone marrow stromal cells (rBMSCs) as well as the attachment, viability and angiogenic gene expression (VEGF and HIF-1α) of human umbilical vein endothelial cells (HUVECs) in MBG-β-TCP scaffolds were significantly upregulated compared with conventional bioactive glass (BG)-modified β-TCP (BG-β-TCP) and pure β-TCP scaffolds. Furthermore, MBG-β-TCP scaffolds significantly enhanced the formation of new bone in vivo as compared to BG-β-TCP and β-TCP scaffolds. The results suggest that application of the MBG nanolayer to modify 3D-printed bioceramic scaffolds offers a new strategy to construct hierarchically porous scaffolds with significantly improved physicochemical and biological properties, such as mechanical properties, osteogenesis, angiogenesis and protein expression for bone tissue

  10. Simple Sample Processing Enhances Malaria Rapid Diagnostic Test Performance

    PubMed Central

    Davis, K. M.; Gibson, L. E.; Haselton, F. R.; Wright, D. W.

    2016-01-01

    Lateral flow immunochromatographic rapid diagnostic tests (RDTs) are the primary form of medical diagnostic used for malaria in underdeveloped nations. Unfortunately, many of these tests do not detect asymptomatic malaria carriers. In order for eradication of the disease to be achieved, this problem must be solved. In this study, we demonstrate enhancement in the performance of six RDT brands when a simple sample-processing step is added to the front of the diagnostic process. Greater than a 4-fold RDT signal enhancement was observed as a result of the sample processing step. This lowered the limit of detection for RDT brands to submicroscopic parasitemias. For the best performing RDTs the limits of detection were found to be as low as 3 parasites/μL. Finally, through individual donor samples, the correlations between donor source, WHO panel detection scores and RDT signal intensities were explored. PMID:24787948

  11. Simple sample processing enhances malaria rapid diagnostic test performance.

    PubMed

    Davis, K M; Gibson, L E; Haselton, F R; Wright, D W

    2014-06-21

    Lateral flow immunochromatographic rapid diagnostic tests (RDTs) are the primary form of medical diagnostic used for malaria in underdeveloped nations. Unfortunately, many of these tests do not detect asymptomatic malaria carriers. In order for eradication of the disease to be achieved, this problem must be solved. In this study, we demonstrate enhancement in the performance of six RDT brands when a simple sample-processing step is added to the front of the diagnostic process. Greater than a 4-fold RDT signal enhancement was observed as a result of the sample processing step. This lowered the limit of detection for RDT brands to submicroscopic parasitemias. For the best performing RDTs the limits of detection were found to be as low as 3 parasites per μL. Finally, through individual donor samples, the correlations between donor source, WHO panel detection scores and RDT signal intensities were explored.

  12. Composite material consisting of microporous β-TCP ceramic and alginate for delayed release of antibiotics.

    PubMed

    Seidenstuecker, Michael; Ruehe, Juergen; Suedkamp, Norbert P; Serr, Annerose; Wittmer, Annette; Bohner, Marc; Bernstein, Anke; Mayr, Hermann O

    2017-03-15

    The aim of this study was to produce a novel composite of microporous β-TCP filled with alginate and Vancomycin (VAN) to prolong the release behavior of the antibiotic for up to 28days. Using the flow chamber developed by the group, porous ceramics in a directional flow were filled with alginates of different composition containing 50mg/mL of antibiotics. After cross-linking the alginate with calcium ions, incubation took place in 10mL double-distilled water for 4weeks at 37°C. At defined times (1, 2, 3, 6, 9, 14, 20 and 28days), the liquid was completely exchanged and analyzed by capillary zone electrophoresis and microtiter trials. For statistical purposes, the mean and standard deviation were calculated and analyzed by ANOVA. The release of VAN from alginate was carried out via an external calcium source over the entire period with concentrations above the minimal inhibitory concentration (MIC). The burst release measured 35.2±1.5%. The release of VAN from alginate with an internal calcium source could only be observed over 14days. The burst release here was 61.9±4.3%. The native alginate's burst release was 54.1±7.8%; that of the sterile alginate 40.5±6.4%. The microtiter experiments revealed efficacy over the entire study period for VAN. The MIC value was determined in the release experiments as well in a range of 0.5-2.0μg/mL against Staphylococcus aureus. Drug release systems based on β-TCP and hydrogels are well documented in literature. However, in all described systems the ceramic, as granule or powder, is inserted into a hydrogel. In our work, we do the opposite, a hydrogel which acts as reservoir for antibiotics is placed into a porous biodegradable ceramic. Eventually, this system should be applied as treatment of bone infections. Contrary to the "granule in hydrogel" composites it has the advantage of mechanical stability. Thus, it can take over functions of the bone during the healing process. For a quicker translation from our scientific

  13. Bone regeneration with active angiogenesis by basic fibroblast growth factor gene transfected mesenchymal stem cells seeded on porous beta-TCP ceramic scaffolds.

    PubMed

    Guo, Xiaodong; Zheng, Qixin; Kulbatski, Iris; Yuan, Quan; Yang, Shuhua; Shao, Zengwu; Wang, Hong; Xiao, Baojun; Pan, Zhengqi; Tang, Shuo

    2006-09-01

    Large segmental bone defect repair remains a clinical and scientific challenge with increasing interest focused on combining gene transfer with tissue engineering techniques. Basic fibroblast growth factor (bFGF) is one of the most prominent osteogenic growth factors that has the potential to accelerate bone healing by promoting the proliferation and differentiation of mesenchymal stem cells (MSCs) and the regeneration of capillary vasculature. However, the short biological half-lives of growth factors may impose severe restraints on their clinical usefulness. Gene-based delivery systems provide a better way of achieving a sustained high concentration of growth factors locally in the defect and delivering a more biologically active product than that achieved by exogenous application of recombinant proteins. The objective of this experimental study was to investigate whether the bFGF gene modified MSCs could enhance the repair of large segmental bone defects. The pcDNA3-bFGF gene transfected MSCs were seeded on biodegradable porous beta tricalcium phosphate (beta-TCP) ceramics and allografted into the 15 mm critical-sized segmental bone defects in the radius of 18 New Zealand White rabbits. The pcDNA3 vector gene transfected MSCs were taken as the control. The follow-up times were 2, 4, 6, 8, 10 and 12 weeks. Scanning electron microscopic, roentgenographic, histologic and immunohistological studies were used to assess angiogenesis and bone regeneration. In vitro, the proliferation and differentiation of bFGF gene transfected MSCs were more active than that of the control groups. In vivo, significantly more new bone formation accompanied by abundant active capillary regeneration was observed in pores of the ceramics loaded with bFGF gene transfected MSCs, compared with control groups. Transfer of gene encoding bFGF to MSCs increases their osteogenic properties by enhancing capillary regeneration, thus providing a rich blood supply for new bone formation. This new b

  14. Spectrum-enhanced Au@ZnO plasmonic nanoparticles for boosting dye-sensitized solar cell performance

    NASA Astrophysics Data System (ADS)

    Liu, Qisheng; Wei, Yunwei; Shahid, Malik Zeeshan; Yao, Mingming; Xu, Bo; Liu, Guangning; Jiang, Kejian; Li, Cuncheng

    2018-03-01

    Spectrum-enhanced Au@ZnO plasmonic nanoparticles (NPs) are developed for fabrication of the dye-sensitized solar cells (DSSCs), and their remarkable enhanced performances are achieved due to Surface Plasmon Resonance (SPR) effects. When being doped different blended amounts of the Au@ZnO NPs within the photoanode layers, various enhanced effects in the SPR-based DSSCs are exhibited. Compared with the power conversion efficiency (PCE, 7.50%) achieved for bare DSSC, device with doped Au@ZnO NPs of 1.93% delivers the top PCE of 8.91%, exhibiting about 20% enhancement. To elaborate the charge transfer process in the Au@ZnO NPs blended DSSCs, the photoluminescence (PL), electrochemical impedance spectra (EIS), etc are performed. We find that both the enhanced SPR absorption properties and the suppressed recombination process of charges contribute much to the improved performance of Au@ZnO-incorporated DSSCs.

  15. Using Thermoelectric Coolers to Enhance Loop Heat Pipe Performance

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Butler, Dan; Ottenstein, Laura; Birur, Gajanana

    2005-01-01

    Contents include the following: Loop Heat Pipe (LHP) operating temperature. LHP start-up issues. How Thermoelectric Cooler (TECs) can enhance LHP performance: start-up; operating temperature control. Experimental studies: LHP with one evaporator and one condenser; LHP with two evaporators and two condensers. Conclusion.

  16. Comparison of the Prevalence of Psychiatric Disorders in Performance-Enhancing Drug Users and Nonuser Bodybuilders.

    PubMed

    Ostovar, Afshin; Haerinejad, Mohammad Javad; Akbarzadeh, Samad; Keshavarz, Mojtaba

    2017-10-01

    Objective: The present study aimed at comparing the prevalence of major psychiatric disorders including major depressive disorder, bipolar disorder, schizophrenia, and generalized anxiety disorder between performance-enhancing drug users and nonuser bodybuilders. Moreover, the prevalence of major psychiatric disorders in bodybuilders was also reported. Method: In this study, 453 athletes were recruited from Bushehr bodybuilding gyms from February to May 2015. A structured questionnaire was used to collect the participants' information, including demographic characteristics, sports' status and performance-enhancing drug use. According to the condition of performance-enhancing drug use, the participants were divided into current users, non-current users, and nonusers. The psychiatric status of the participants was evaluated using DSM-IV diagnostic criteria for major depressive disorder, bipolar disorder, generalized anxiety disorder, and schizophrenia. We also asked about the acute psychotic disturbances after using performance-enhancing drugs, alcohol use, and history of aggressive behavior in bodybuilders. Data were analyzed using one-way analysis of variance and chi-square tests. Results: Prevalence of major depressive disorder, bipolar disorder, schizophrenia, generalized anxiety disorder, and the overall prevalence of psychiatric disorders in the bodybuilders was 19.7%, 3.8%, 1.5%, 16.6%, and 26.7%, respectively. After using performance-enhancing drugs, 33% of the bodybuilders had experienced acute psychological disturbances. There were no significant differences between current, non-current, and nonuser bodybuilding athletes in the measured psychiatric disorders. Conclusion: Prevalence of psychiatric disorders was not significantly different in performance-enhancing drug users and nonusers. Thus, it can be concluded that performance-enhancing drugs do not increase the risk of psychiatric disorders in bodybuilders.

  17. Enhancement on Wingate Anaerobic Test Performance With Hyperventilation.

    PubMed

    Leithäuser, Renate M; Böning, Dieter; Hütler, Matthias; Beneke, Ralph

    2016-07-01

    Relatively long-lasting metabolic alkalizing procedures such as bicarbonate ingestion have potential for improving performance in long-sprint to middle-distance events. Within a few minutes, hyperventilation can induce respiratory alkalosis. However, corresponding performance effects are missing or equivocal at best. To test a potential performance-enhancing effect of respiratory alkalosis in a 30-s Wingate Anaerobic Test (WAnT). 10 men (mean ± SD age 26.6 ± 4.9 y, height 184.4 ± 6.1 cm, body-mass test 1 80.7 ± 7.7 kg, body-mass test 2 80.4 ± 7.2 kg, peak oxygen uptake 3.95 ± 0.43 L/min) performed 2 WAnTs, 1 with and 1 without a standardized 15-min hyperventilation program pre-WAnT in randomized order separated by 1 wk. Compared with the control condition, hyperventilation reduced (all P < .01) pCO2 (40.5 ± 2.8 vs 22.5 ± 1.6 mm Hg) and HCO3 - (25.5 ± 1.7 vs 22.7 ± 1.6 mmol/L) and increased (all P < .01) pH (7.41 ± 0.01 vs 7.61 ± 0.03) and actual base excess (1.4 ± 1.4 vs 3.2 ± 1.6 mmol/L) pre-WAnT with an ergogenic effect on WAnT average power (681 ± 41 vs 714 ± 44 W) and total metabolic energy (138 ± 12 vs. 144 ± 13 kJ) based on an increase in glycolytic energy (81 ± 13 vs 88 ± 13 kJ). Hyperventilation-induced respiratory alkalosis can enhance WAnT cycling sprint performance well in the magnitude of what is seen after successful bicarbonate ingestion.

  18. The impact of PET/CT scanning on the size of target volumes, radiation exposure of organs at risk, TCP and NTCP, in the radiotherapy planning of non-small cell lung cancer.

    PubMed

    Vojtíšek, Radovan; Mužík, Jan; Slampa, Pavel; Budíková, Marie; Hejsek, Jaroslav; Smolák, Petr; Ferda, Jiří; Fínek, Jindřich

    2014-05-01

    To compare radiotherapy plans made according to CT and PET/CT and to investigate the impact of changes in target volumes on tumour control probability (TCP), normal tissue complication probability (NTCP) and the impact of PET/CT on the staging and treatment strategy. Contemporary studies have proven that PET/CT attains higher sensitivity and specificity in the diagnosis of lung cancer and also leads to higher accuracy than CT alone in the process of target volume delineation in NSCLC. Between October 2009 and March 2012, 31 patients with locally advanced NSCLC, who had been referred to radical radiotherapy were involved in our study. They all underwent planning PET/CT examination. Then we carried out two separate delineations of target volumes and two radiotherapy plans and we compared the following parameters of those plans: staging, treatment purpose, the size of GTV and PTV and the exposure of organs at risk (OAR). TCP and NTCP were also compared. PET/CT information led to a significant decrease in the sizes of target volumes, which had the impact on the radiation exposure of OARs. The reduction of target volume sizes was not reflected in the significant increase of the TCP value. We found that there is a very strong direct linear relationship between all evaluated dosimetric parameters and NTCP values of all evaluated OARs. Our study found that the use of planning PET/CT in the radiotherapy planning of NSCLC has a crucial impact on the precise determination of target volumes, more precise staging of the disease and thus also on possible changes of treatment strategy.

  19. Effect of intermittent administration of teriparatide on the mechanical and histological changes in bone grafted with β-tricalcium phosphate using a rabbit bone defect model

    PubMed Central

    Komatsu, Jun; Nagura, Nana; Iwase, Hideaki; Igarashi, Mamoru; Ohbayashi, Osamu; Nagaoka, Isao; Kaneko, Kazuo

    2018-01-01

    Grafting β-tricalcium phosphate (TCP) is a well-established method for restoring bone defects; however, there is concern that the mechanical stability of the grafted β-TCP is not maintained during bone translation. Teriparatide has an anabolic effect, stimulating bone formation and increasing bone mineral density for the treatment of osteoporosis. The aim of the present study was to evaluate the effect of intermittent teriparatide treatment on changes in bone grafted with β-TCP using a rabbit bone defect model. Bone defects (5×15 mm) were created in the distal femoral condyle of Japanese white rabbits, and β-TCP granules of two different total porosities were manually grafted. Teriparatide (40 µg/kg) or 0.2% rabbit serum albumin solution as a vehicle control was subcutaneously injected three times per week following the surgery. At 4 or 8 weeks post-surgery, serum samples were obtained and the levels of γ-carboxylated osteocalcin (Gla-OC) were quantified using ELISA. Histomorphometry was also performed using sections of graft sites following staining for tartrate resistant acid phosphatase. Activity and mechanical strength (maximum shear strength, maximum shear stiffness and total energy absorption) were evaluated using an axial push-out load to failure test. Teriparatide treatment significantly increased (P<0.05) the serum levels of Gla-OC, a specific marker for bone formation, suggesting that teriparatide enhances bone formation in β-TCP-grafted rabbits. Furthermore teriparatide increased the degradation of β-TCP by bone remodeling (P<0.05) and promoted the formation of new bone following application of the graft compared with the control group (P<0.01). Furthermore, teriparatide suppressed the reduction in mechanical strength (P<0.05) during bone translation in bone defects grafted with β-TCP. The results of the present study demonstrate that teriparatide is effective in maintaining the mechanical stability of grafted β-TCP, possibly by promoting new

  20. Metal-air cell with performance enhancing additive

    DOEpatents

    Friesen, Cody A; Buttry, Daniel

    2015-11-10

    Systems and methods drawn to an electrochemical cell comprising a low temperature ionic liquid comprising positive ions and negative ions and a performance enhancing additive added to the low temperature ionic liquid. The additive dissolves in the ionic liquid to form cations, which are coordinated with one or more negative ions forming ion complexes. The electrochemical cell also includes an air electrode configured to absorb and reduce oxygen. The ion complexes improve oxygen reduction thermodynamics and/or kinetics relative to the ionic liquid without the additive.