Changing the values of parameters on lot size reorder point model

Directory of Open Access Journals (Sweden)

Chang Hung-Chi

2003-01-01

Full Text Available The Just-In-Time (JIT philosophy has received a great deal of attention. Several actions such as improving quality, reducing setup cost and shortening lead time have been recognized as effective ways to achieve the underlying goal of JIT. This paper considers the partial backorders, lot size reorder point inventory system with an imperfect production process. The objective is to simultaneously optimize the lot size, reorder point, process quality, setup cost and lead time, constrained on a service level. We assume the explicit distributional form of lead time demand is unknown but the mean and standard deviation are given. The minimax distribution free approach is utilized to solve the problem and a numerical example is provided to illustrate the results. .

TCP Performance Enhancement for UMTS Access Network

DEFF Research Database (Denmark)

Hu, Liang

2008-01-01

is between UMTS access network and Internet. The split proxy divides the bandwidth delay product into two parts, resulting in two TCP connections with smaller bandwidth delay products. Simulation results show, the split TCP proxy can significantly improve the TCP performance under high bit rate DCH channel......We aim at optimize the TCP performance over UMTS access network challenged by the large delay bandwidth product that is mainly caused by the latency from the link layer ARQ retransmissions and diversity technique at physical layer. We propose to place a split TCP proxy at GGSN nodes which...

A New TCP Congestion Control Supporting RTT-Fairness

Science.gov (United States)

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.

Internetworking with TCP/IP

CERN Document Server

Comer, Douglas E

2014-01-01

An internationally best-selling, conceptual introduction to the TCP/IP protocols and Internetworking, this book interweaves a clear discussion of fundamentals and scientific principles with details and examples drawn from the latest technologies. Leading author Douglas Comer covers layering and packet formats for all the Internet protocols, includingTCP, IPv4, IPv6, DHCP, and DNS. In addition, the text explains new trends in Internet systems, including packet classification, Software Defined Networking (SDN), and mesh protocols used in The Internet of Things. The text is appropriate for individuals interested in learning more about TCP/IP protocols, Internet architecture, and current networking technologies, as well as engineers who build network systems. It is suitable for junior to graduate-level courses in Computer Networks, Data Networks, Network Protocols, and Internetworking.

TCP Packet Trace Analysis. M.S. Thesis

Science.gov (United States)

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.

Analisis Throughput Varian TCP Pada Model Jaringan WiMAX

Directory of Open Access Journals (Sweden)

Medi Taruk

2016-07-01

Full Text Available Transmission Control Protocol (TCP is a protocol that works at the transport layer of the OSI model. TCP was originally designed more destined for a wired network. However, to meet the need for the development of a very fast network technology based on the needs of the use by the user, it needs further development to the use of TCP on wireless devices. One implementation of a wireless network based on Worldwide Interoperability for Microwave Access (WiMAX network is a model that offers a variety advantage, particularly in terms of access speed. In this case, use NS-2 to see throughput at TCP variants tested, namely TCP-Tahoe, TCP-Reno, TCP-Vegas, and TCP-SACK over WiMAX network model, with few observations scenarios. The first is a look at each of these variants throughput of TCP when only one particular variant of the work in the network. Second observe all variants of TCP throughput at the same time and have the equivalent QoS, but with the possibility of a small congestion based on the capacity of the link is made sufficient. Third observed throughput with multi congestion. In WiMAX network has scheduling services are UGS, rtPS and ertPS using UDP protocol and nrtPS and BE using the TCP Protocol. By using the software network simulator (NS-2 to obtain performance comparison TCP protocol-based services on the WiMAX network with QoS parameters are throughput, packet loss, fairness and time delay.

Transformation and biodegradation of 1,2,3-trichloropropane (TCP).

Science.gov (United States)

Samin, Ghufrana; Janssen, Dick B

2012-09-01

1,2,3-Trichloropropane (TCP) is a persistent groundwater pollutant and a suspected human carcinogen. It is also is an industrial chemical waste that has been formed in large amounts during epichlorohydrin manufacture. In view of the spread of TCP via groundwater and its toxicity, there is a need for cheap and efficient technologies for the cleanup of TCP-contaminated sites. In situ or on-site bioremediation of TCP is an option if biodegradation can be achieved and stimulated. This paper presents an overview of methods for the remediation of TCP-contaminated water with an emphasis on the possibilities of biodegradation. Although TCP is a xenobiotic chlorinated compound of high chemical stability, a number of abiotic and biotic conversions have been demonstrated, including abiotic oxidative conversion in the presence of a strong oxidant and reductive conversion by zero-valent zinc. Biotransformations that have been observed include reductive dechlorination, monooxygenase-mediated cometabolism, and enzymatic hydrolysis. No natural organisms are known that can use TCP as a carbon source for growth under aerobic conditions, but anaerobically TCP may serve as electron acceptor. The application of biodegradation is hindered by low degradation rates and incomplete mineralization. Protein engineering and genetic modification can be used to obtain microorganisms with enhanced TCP degradation potential.

Microwave sintering of nano size powder β-TCP bioceramics

Directory of Open Access Journals (Sweden)

Mirhadi B.

2014-01-01

Full Text Available A nano sized beta tricalcium phosphate (β-TCP powder was conventional sintered (CS and microwave sintered (MW, in order to obtain dense β-TCP ceramics. In this work the effect of microwave sintering conditions on the microstructure, phase composition and mechanical properties of materials based on tricalcium phosphate (TCP was investigated by SEM (scanning electron microscopyand XRD(X-ray diffraction and then compared with conventional sintered samples. Nano-size β-TCP powders with average grain size of 80 nm were prepared by the wet chemical precipitation method with calcium nitrate and diammonium hydrogen phosphate as calcium and phosphorus precursors, respectively. The precipitation process employed was also found to be suitable for the production of submicrometre β-TCP powder in situ. The β-TCP samples microwave (MW sintered for 15 min at 1100°C, with average grain size of 3μm, showed better densification, higher density and certainly higher hardness than samples conventionally sintered for 2 h at the same temperature. By comparing sintered and MW sintered β-TCP samples, it was concluded that MW sintered β-TCP samples have superior mechanical properties.

Contrast-enhanced 3D MR angiography of the chest and abdomen with breath-holding using phase reordering

International Nuclear Information System (INIS)

Amanuma, Makoto; Sugimoto, Eiichi; Enomoto, Kyoko; Watabe, Tsuneya; Heshiki, Atsuko; Hirata, Hisashi; Kimura, Toshihiko; Takizawa, Osamu.

1995-01-01

This report presents the feasibility of phase-reordered contrast-enhanced three-dimensional MR angiography in 32 consecutive patients with vascular abnormalities in the chest and abdomen. To suppress motion artifacts due to respiratory corruption, a phase-reordering technique was introduced so that the low frequency components of the phase data were obtained first during the imaging period. Image quality and degree of motion suppression were assessed by four radiologists independently without information on breath-holding time. Abnormalities were detected in 30 cases (93.8%), and their extent was correctly assessed in 28 cases (87.5%). More confident assessment was possible in abnormalities of the pulmonary vessels and thoracic aorta than in those of the abdominal aorta and portal venous system. With phase reordering, more than 20 seconds of breath-holding ensured image quality sufficient to correctly assess the vascular abnormalities. While this technique is easy and requires only single breath-holding, it can provide excellent MRA without slice-to-slice spatial misregistration. (author)

Chitosan Fibers Modified with HAp/β–TCP Nanoparticles

Directory of Open Access Journals (Sweden)

Dariusz Wawro

2011-10-01

Full Text Available This paper describes a method for preparing chitosan fibers modified with hydroxyapatite (HAp, tricalcium phosphate (β-TCP, and HAp/β-TCP nanoparticles. Fiber-grade chitosan derived from the northern shrimp (Pandalus borealis and nanoparticles of tricalcium phosphate (β-TCP and hydroxyapatite (HAp suspended in a diluted chitosan solution were used in the investigation. Diluted chitosan solution containing nanoparticles of Hap/β-TCP was introduced to a 5.16 wt% solution of chitosan in 3.0 wt% acetic acid. The properties of the spinning solutions were examined. Chitosan fibers modified with nanoparticles of HAp/β-TCP were characterized by a level of tenacity and calcium content one hundred times higher than that of regular chitosan fibers.

Transformation and biodegradation of 1,2,3-trichloropropane (TCP)

OpenAIRE

Samin, Ghufrana; Janssen, Dick B.

2012-01-01

Purpose 1,2,3-Trichloropropane (TCP) is a persistent groundwater pollutant and a suspected human carcinogen. It is also is an industrial chemical waste that has been formed in large amounts during epichlorohydrin manufacture. In view of the spread of TCP via groundwater and its toxicity, there is a need for cheap and efficient technologies for the cleanup of TCP-contaminated sites. In situ or on-site bioremediation of TCP is an option if biodegradation can be achieved and stimulated. This pap...

A novel implementation of TCP Vegas for optical burst switched networks

KAUST Repository

Shihada, Basem

2010-07-01

TCP performance over bufferless Optical Burst Switched (OBS) networks could be significantly degraded due to the misinterpretation of network congestion status (referred to as false congestion detection). It has been reported that burst retransmission in the OBS domain can improve the TCP throughput by hiding burst loss events from the upper TCP layer, which can effectively reduce the congestion window fluctuation at the expense of introducing additional delay. However, the additional delay may cause performance degradation for delay-based TCP implementations that are sensitive to packet round trip time in estimating the network congestion status. In this paper, a novel implementation of TCP Vegas that adopts a threshold-based mechanism is proposed for identifying the network congestion status in OBS networks. Analytical models are developed to evaluate the throughput of conventional TCP Vegas and threshold-based Vegas over OBS networks with burst retransmission. Simulation is conducted to validate the analytical model and to compare threshold-based Vegas with a number of legacy TCP implementations, such as TCP Sack and TCP Reno. The analytical model can be used to obtain a proper threshold value that results in an optimal steady state TCP throughput.

The power of reordering for online minimum makespan scheduling

OpenAIRE

Englert, Matthias; Özmen, Deniz; Westermann, Matthias

2014-01-01

In the classic minimum makespan scheduling problem, we are given an input sequence of jobs with processing times. A scheduling algorithm has to assign the jobs to m parallel machines. The objective is to minimize the makespan, which is the time it takes until all jobs are processed. In this paper, we consider online scheduling algorithms without preemption. However, we do not require that each arriving job has to be assigned immediately to one of the machines. A reordering buffer with limited...

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

Energy Technology Data Exchange (ETDEWEB)

Xie Xinhui; Wang Xinluan; Zhang Ge; He Yixin; Liu Zhong; Peng Jiang; Qin Ling [Department of Orthopaedics and Traumatology, Chinese University of Hong Kong (Hong Kong); Wang Xiaohong; He Kai [Key Laboratory for Advanced Materials Processing Technology, Ministry of Education and Center of Organ Manufacturing, Department of Mechanical Engineering, Tsinghua University, Beijing (China); Leng Yang, E-mail: lingqin@cuhk.edu.h [Department of Mechanical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

2010-10-01

Phytomolecules may chemically bind to scaffold materials for medical applications. The present study used an osteoconductive porous poly(l-lactide-co-glycolide)/tricalcium phosphate (PLGA/TCP) to incorporate an exogenous phytoestrogenic molecule icaritin to form a PLGA/TCP/icaritin composite scaffold material with potential slow release of icaritin during scaffold degradation. Accordingly, the present study was designed to investigate its in vitro degradation characteristics and the release pattern of icaritin at three different doses (74 mg, 7.4 mg and 0.74 mg per 100 g PLGA/TCP, i.e. in the PLGA/TCP/icaritin-H, -M and -L groups, respectively). A PLGA/TCP/icaritin porous composite scaffold was fabricated using a computer-controlled printing machine. The PLGA/TCP/icaritin scaffolds were incubated in saline at 37 {sup 0}C for 12 weeks and the pure PLGA/TCP scaffold served as a control. During the 12 weeks in vitro degradation, the scaffolds in all four groups showed changes, including a decrease in weight, volume and pore size of the composite scaffold, while there was a decrease in acidity and an increase in Ca and lactic acid concentrations in the degradation medium, especially after 7 weeks. The rate of degradation was explained by the relationship with the content of icaritin incorporated into the scaffolds. The higher the icaritin content in the scaffolds, the slower the degradation could be observed during 12 weeks. After 12 weeks, the SEM showed that the surface of the PLGA/TCP and PLGA/TCP/icaritin-L groups was relatively smooth with a gradual decrease in number and size of the micropores, while the porous morphology on the surface of the PLGA/TCP/icaritin-M and PLGA/TCP/icaritin-H groups was partly maintained, accompanied by a decrease in phosphate (P) and calcium (Ca) contents at the surface. Though the mechanical property of the PLGA/TCP/icaritin scaffold decreased after degradation, its porous structure was maintained, which was essential for cell

Global Connections for Lasting Impressions: Experiential Learning about TCP

Science.gov (United States)

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.

Performance Analysis of TCP Enhancements in Satellite Data Networks

Science.gov (United States)

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.

Study of dynamical properties in β-Tcp/Ch layers

International Nuclear Information System (INIS)

Mina, A.; Caicedo, J. C.; Aperador, W.

2015-01-01

β-Tricalcium phosphate/Chitosan (β-Tcp/Ch) coatings were deposited on 316l stainless steel (316l Ss) substrates by a cathodic electrodeposition technique at different coating compositions. The crystal lattice arrangements were analyzed by X-ray diffraction, and the results indicated that the crystallographic structure of β-Tcp was affected by the inclusion of the chitosan content. The changes in the surface morphology as a function of increasing chitosan in the coatings via scanning electron microscopy and atomic force microscopy showed the root-mean squares hardness of the β-Tcp/Ch coatings decreased by further increasing chitosan percentage. The elastic-plastic characteristics of the coatings were determined by conducting nano indentation test, indicating that the increase if chitosan percentage is directly related to increasing the hardness and elastic modulus of the β-Tcp/Ch coatings. Tribological characterization was performed by scratch test and pin-on-disk test to analyze the changes in the surface wear the β-Tcp/Ch coatings. Finally, the results indicated an improvement in the mechanical and tribological properties of the β-Tcp/Ch coatings as a function of increasing of the chitosan percentage. (Author)

Study of dynamical properties in β-Tcp/Ch layers

Energy Technology Data Exchange (ETDEWEB)

Mina, A.; Caicedo, J. C. [Universidad del Valle, Tribology, Powder Metallurgy and Processing of Solid Recycled Research Group, Cali, Valle del Cauca (Colombia); Aperador, W., E-mail: jacaicedoangulo1@gmail.com [Universidad Militar Nueva Granada, Departamento de Ingenieria, 80 Entrada A La KR11 No. 101, Bogota (Colombia)

2015-07-01

β-Tricalcium phosphate/Chitosan (β-Tcp/Ch) coatings were deposited on 316l stainless steel (316l Ss) substrates by a cathodic electrodeposition technique at different coating compositions. The crystal lattice arrangements were analyzed by X-ray diffraction, and the results indicated that the crystallographic structure of β-Tcp was affected by the inclusion of the chitosan content. The changes in the surface morphology as a function of increasing chitosan in the coatings via scanning electron microscopy and atomic force microscopy showed the root-mean squares hardness of the β-Tcp/Ch coatings decreased by further increasing chitosan percentage. The elastic-plastic characteristics of the coatings were determined by conducting nano indentation test, indicating that the increase if chitosan percentage is directly related to increasing the hardness and elastic modulus of the β-Tcp/Ch coatings. Tribological characterization was performed by scratch test and pin-on-disk test to analyze the changes in the surface wear the β-Tcp/Ch coatings. Finally, the results indicated an improvement in the mechanical and tribological properties of the β-Tcp/Ch coatings as a function of increasing of the chitosan percentage. (Author)

Compatibility Issues of IPSec and TCP in Wireless Networks

Institute of Scientific and Technical Information of China (English)

ZHAO Hai-yang; XIN Yang

2004-01-01

Due to the problems arising when the Transmission Control Protocol (TCP) is applied over wireless networks, many TCP performance enhancement mechanisms have been proposed. However, such mechanisms aren't compatible with IPSec protocol. The paper reviews the TCP performance enhancement mechanisms in wireless networks. Then the conflicts between them are analyzed. Several proposals for solving theconflicts are discussed, and their benefit and limitations are examined.

Cross-layer TCP Performance Analysis in IEEE 802.11 Vehicular Environments

Directory of Open Access Journals (Sweden)

T. Janevski

2014-06-01

Full Text Available In this paper we provide a performance analysis of TCP in IEEE 802.11 vehicular environments for different well-known TCP versions, such as Tahoe, Reno, New Reno, Vegas, and Sack. The parameters of interest from the TCP side are the number of Duplicate Acknowledgements - DupAck, and the number of Delayed Acknowledgements - DelAck, while on the wireless network side the analyzed parameter is the interface queue - IFQ. We have made the analysis for the worst-case distance scenario for single-hop and worst-case multihop vehicular environments. The results show that the number of wireless hops in vehicular environments significantly reduces the TCP throughput. The best average performances considering all scenarios were obtained for TCP Vegas. However, the results show that the interface queue at wireless nodes should be at least five packets or more. On the other side, due to shorter distances in the vehicular wireless network, results show possible flexibility of using different values for the DupAck without degradation of the TCP throughput. On the other side, the introduction of the DelAck parameter provides enhancement in the average TCP throughput for all TCP versions.

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

Science.gov (United States)

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.

Analysis of Malicious Traffic in Modbus/TCP Communications

Science.gov (United States)

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.

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

International Nuclear Information System (INIS)

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

2016-01-01

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. (paper)

Application Filters for TCP/IP Industrial Automation Protocols

Science.gov (United States)

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

The use of firewalls is a common approach usually meant to secure Automation Technology (AT) from Information Technology (TI) networks. This work proposes a filtering system for TCP/IP-based automation networks in which only certain kind of industrial traffic is permitted. All network traffic which does not conform with a proper industrial protocol pattern or with specific rules for its actions is supposed to be abnormal and must be blocked. As a case study, we developed a seventh layer firewall application with the ability of blocking spurious traffic, using an IP packet queueing engine and a regular expression library.

Comparative histomorphometric analysis between α-Tcp cement and β-Tcp/Ha granules in the bone repair of rat calvaria

Directory of Open Access Journals (Sweden)

Gisela Grandi

2011-03-01

Full Text Available This study compared the effect of two bioceramics on the process of bone repair: α-tricalcium phosphate (α-TCP cement and β-tricalcium phosphate hydroxyapatite particles (β-TCP/HA. Calvarial defects were created in 50 rats, divided into two groups (α and β/HA. Software was used at 7, 21, 60, 90 and 120 days to assess bone formation. Mean new bone formation rates were as follows: α group, 1.6% at 7 days, 5.24% at 21 days, 24% at 60 days, 30.21% at 90 days and 50.59% at 120 days; β/HA group, 1.94% at 7 days, 2.53% at 21 days, 12.47% at 60 days, 26.84% at 90 days and 38.82% at 120 days; control group, 0.15% at 7 days, 10.12% at 21 days, 15.10% at 60 days, 18.94% at 90 days, 48.50% at 120 days. Both materials are osteoconductive and biocompatible. Perhaps the larger rate of new bone formation observed in the α-TCP group, it also occurs in the β-TCP/HA group within a longer time period.

FAST TCP over optical burst switched networks: Modeling and stability analysis

KAUST Repository

Shihada, Basem

2013-04-01

FAST TCP is important for promoting data-intensive applications since it can cleverly react to both packet loss and delay for detecting network congestion. This paper provides a continuous time model and extensive stability analysis of FAST TCP congestion-control mechanism in bufferless Optical Burst Switched Networks (OBS). The paper first shows that random burst contentions are essential to stabilize the network, but cause throughput degradation in FAST TCP flows when a burst with all the packets from a single round is dropped. Second, it shows that FAST TCP is vulnerable to burst delay and fails to detect network congestion due to the little variation of round-trip time, thus unstable. Finally it shows that introducing extra delays by implementing burst retransmission stabilizes FAST TCP over OBS. The paper proves that FAST TCP is not stable over barebone OBS. However, it is locally, exponentially, and asymptotically stable over OBS with burst retransmission.

TCP Throughput Profiles Using Measurements over Dedicated Connections

Energy Technology Data Exchange (ETDEWEB)

Rao, Nageswara S. [ORNL; Liu, Qiang [ORNL; Sen, Satyabrata [ORNL; Towsley, Don [University of Massachusetts, Amherst; Vardoyan, Gayane [University of Massachusetts, Amherst; Kettimuthu, R. [Argonne National Laboratory (ANL); Foster, Ian [University of Chicago

2017-06-01

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, in 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.

A Novel Congestion Detection Scheme in TCP Over OBS Networks

KAUST Repository

Shihada, Basem

2009-02-01

This paper introduces a novel congestion detection scheme for high-bandwidth TCP flows over optical burst switching (OBS) networks, called statistical additive increase multiplicative decrease (SAIMD). SAIMD maintains and analyzes a number of previous round-trip time (RTTs) at the TCP senders in order to identify the confidence with which a packet loss event is due to network congestion. The confidence is derived by positioning short-term RTT in the spectrum of long-term historical RTTs. The derived confidence corresponding to the packet loss is then taken in the developed policy for TCP congestion window adjustment. We will show through extensive simulation that the proposed scheme can effectively solve the false congestion detection problem and significantly outperform the conventional TCP counterparts without losing fairness. The advantages gained in our scheme are at the expense of introducing more overhead in the SAIMD TCP senders. Based on the proposed congestion control algorithm, a throughput model is formulated, and is further verified by simulation results.

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

Science.gov (United States)

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.

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

Directory of Open Access Journals (Sweden)

Yifei Lu

2017-01-01

Full Text Available 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.

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

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Magdalena J. Mazur

2017-11-01

Full Text Available 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.

Improving the quantum cost of reversible Boolean functions using reorder algorithm

Science.gov (United States)

Ahmed, Taghreed; Younes, Ahmed; Elsayed, Ashraf

2018-05-01

This paper introduces a novel algorithm to synthesize a low-cost reversible circuits for any Boolean function with n inputs represented as a Positive Polarity Reed-Muller expansion. The proposed algorithm applies a predefined rules to reorder the terms in the function to minimize the multi-calculation of common parts of the Boolean function to decrease the quantum cost of the reversible circuit. The paper achieves a decrease in the quantum cost and/or the circuit length, on average, when compared with relevant work in the literature.

Area law and vacuum reordering in harmonic networks

International Nuclear Information System (INIS)

Riera, A.; Latorre, J. I.

2006-01-01

We review a number of ideas related to area-law scaling of the geometric entropy from the point of view of condensed matter, quantum field theory, and quantum information. An explicit computation in arbitrary dimensions of the geometric entropy of the ground state of a discretized scalar free field theory shows the expected area law result. In this case, area-law scaling is a manifestation of a deeper reordering of the vacuum produced by majorization relations. Furthermore, the explicit control on all the eigenvalues of the reduced density matrix allows for a verification of entropy loss along the renormalization group trajectory driven by the mass term. A further result of our computation shows that single-copy entanglement also obeys area law scaling, majorization relations, and decreases along renormalization group flows

Biclustering via optimal re-ordering of data matrices in systems biology: rigorous methods and comparative studies

Directory of Open Access Journals (Sweden)

Feng Xiao-Jiang

2008-10-01

Full Text Available Abstract Background The analysis of large-scale data sets via clustering techniques is utilized in a number of applications. Biclustering in particular has emerged as an important problem in the analysis of gene expression data since genes may only jointly respond over a subset of conditions. Biclustering algorithms also have important applications in sample classification where, for instance, tissue samples can be classified as cancerous or normal. Many of the methods for biclustering, and clustering algorithms in general, utilize simplified models or heuristic strategies for identifying the "best" grouping of elements according to some metric and cluster definition and thus result in suboptimal clusters. Results In this article, we present a rigorous approach to biclustering, OREO, which is based on the Optimal RE-Ordering of the rows and columns of a data matrix so as to globally minimize the dissimilarity metric. The physical permutations of the rows and columns of the data matrix can be modeled as either a network flow problem or a traveling salesman problem. Cluster boundaries in one dimension are used to partition and re-order the other dimensions of the corresponding submatrices to generate biclusters. The performance of OREO is tested on (a metabolite concentration data, (b an image reconstruction matrix, (c synthetic data with implanted biclusters, and gene expression data for (d colon cancer data, (e breast cancer data, as well as (f yeast segregant data to validate the ability of the proposed method and compare it to existing biclustering and clustering methods. Conclusion We demonstrate that this rigorous global optimization method for biclustering produces clusters with more insightful groupings of similar entities, such as genes or metabolites sharing common functions, than other clustering and biclustering algorithms and can reconstruct underlying fundamental patterns in the data for several distinct sets of data matrices arising

Sodium-Induced Reordering of Atomic Stacks in Black Phosphorus

KAUST Repository

Cheng, Yingchun

2017-01-12

While theoretical simulations predict contradictory results about how the intercalation of foreign metal atoms affects the order of atomic layers in black phosphorus (BP), no direct experimental visualization work has yet clarified this ambiguity. By in situ electrochemical sodiation of BP inside a high-resolution transmission electron microscope and first-principles calculations, we found that sodium intercalation induces a relative glide of/ ⟨010⟩ {001}, resulting in reordering of atomic stacks from AB to AC in BP. The observed local amorphization in our experiments is triggered by lattice constraints. We predict that intercalation of sodium or other metal atoms introduces n-type carriers in BP. This potentially opens a new field for two-dimensional electronics based on BP.

Sodium-Induced Reordering of Atomic Stacks in Black Phosphorus

KAUST Repository

Cheng, Yingchun; Zhu, Yihan; Han, Yu; Liu, Zhongyuan; Yang, Bingchao; Nie, Anmin; Huang, Wei; Shahbazian-Yassar, Reza; Mashayek, Farzad

2017-01-01

While theoretical simulations predict contradictory results about how the intercalation of foreign metal atoms affects the order of atomic layers in black phosphorus (BP), no direct experimental visualization work has yet clarified this ambiguity. By in situ electrochemical sodiation of BP inside a high-resolution transmission electron microscope and first-principles calculations, we found that sodium intercalation induces a relative glide of/ ⟨010⟩ {001}, resulting in reordering of atomic stacks from AB to AC in BP. The observed local amorphization in our experiments is triggered by lattice constraints. We predict that intercalation of sodium or other metal atoms introduces n-type carriers in BP. This potentially opens a new field for two-dimensional electronics based on BP.

Genomewide analysis of TCP transcription factor gene family in ...

Indian Academy of Sciences (India)

Home; Journals; Journal of Genetics; Volume 93; Issue 3. Genomewide ... Teosinte branched1/cycloidea/proliferating cell factor1 (TCP) proteins are a large family of transcriptional regulators in angiosperms. They are ... To the best of our knowledge, this is the first study of a genomewide analysis of apple TCP gene family.

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

Science.gov (United States)

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.

TCP Congestion Control for the Networks with Markovian Jump Parameters

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MOMENI, H. R.

2011-05-01

Full Text Available This paper is concerned with the problem of TCP congestion control for the class of communication networks with random parameters. The linear dynamic model of TCP New Reno in congestion avoidance mode is considered which contains round trip delays in both state and input. The randomness of link capacity, round trip time delay and the number of TCP sessions is modeled with a continuous-time finite state Markov process. An Active Queue Management (AQM technique is then used to adjust the queue level of the congested link to a predefined value. For this purpose, a dynamic output feedback controller with mode dependent parameters is synthesized to stochastically stabilize the TCP/AQM dynamics. The procedure of the control synthesis is implemented by solving a linear matrix inequality (LMI. The results are tested within a simulation example and the effectiveness of the proposed design method is verified.

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

Science.gov (United States)

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.

MAC-layer protocol for TCP fairness in Wireless Mesh Networks

KAUST Repository

Nawab, Faisal; Jamshaid, Kamran; Shihada, Basem; Ho, Pin-Han

2012-01-01

In this paper we study the interactions of TCP and IEEE 802.11 MAC in Wireless Mesh Networks (WMNs). We use a Markov chain to capture the behavior of TCP sessions, particularly the impact on network throughput performance due to the effect of queue

Application of Azolla for 2, 4, 6-Trichlorophenol (TCP Removal from Aqueous Solutions

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Mohammad Ali Zazouli

2013-11-01

Full Text Available Background & Aims of the Study: The 2, 4, 6-Trichlorophenol (TCP is a phenolic compound which it can produce adverse effects on human and environment. Therefore, the removal of these compounds is necessary. The aim of this study is the investigation of TCP removal by using Azolla filiculoides biomass. Materials & Methods: The Azolla biomass was dried in the sunlight, and then it was crushed and sieved to particle sizes in range of 1-2 mm. Next treated with 0.1M HCl for a period of 5h. The Azolla was washed with distilled water and it was used as adsorbent. The effect of operating parameters such as pH, contact time, TCP concentration and adsorbent dose on the TCP removal efficiency was investigated. The residues concentration of TCP was measured by spectrophotometer in λ max of 296 nm. Results: In optimum condition (pH 3, contact time 120 min , adsorbent dose 10 gr/l and TCP concentration 10 ppm, Azolla was able to remove 95% of TCP from aqueous solutions. The equilibrium data follows the Langmuir isotherm and the proper kinetic model is pseudo-second model. Conclusions: Adsorption process by Azolla filiculoides is an efficient method for removal of 2, 4, 6-Trichlorophenol from aqueous solutions.

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

Science.gov (United States)

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.

OpenVPN and Multipath TCP

OpenAIRE

Paulus, Aloïs

2015-01-01

Testing the performances of using Multipath TCP and OpenVPN on a consumer grade router to aggregate multiple Internet connections and provide a fast and reliable connection to individuals and small companies. Master [60] en sciences informatiques, Université catholique de Louvain, 2015

Order-disorder-reorder process in thermally treated dolomite samples: a combined powder and single-crystal X-ray diffraction study

Science.gov (United States)

Zucchini, A.; Comodi, P.; Katerinopoulou, A.; Balic-Zunic, T.; McCammon, C.; Frondini, F.

2012-04-01

A combined powder and single-crystal X-ray diffraction analysis of dolomite [CaMg(CO3)2] heated to 1,200°C at 3 GPa was made to study the order-disorder-reorder process. The order/disorder transition is inferred to start below 1,100°C, and complete disorder is attained at approximately 1,200°C. Twinned crystals characterized by high internal order were found in samples annealed over 1,100°C, and their fraction was found to increase with temperature. Evidences of twinning domains combined with probable remaining disordered portions of the structure imply that reordering processes occur during the quench. Twin domains are hereby proposed as a witness to thermally induced intra-layer-type cation disordering.

Four dimensional magnetic resonance imaging with retrospective k-space reordering: A feasibility study

International Nuclear Information System (INIS)

Liu, Yilin; Yin, Fang-Fang; Cai, Jing; Chen, Nan-kuei; Chu, Mei-Lan

2015-01-01

Purpose: Current four dimensional magnetic resonance imaging (4D-MRI) techniques lack sufficient temporal/spatial resolution and consistent tumor contrast. To overcome these limitations, this study presents the development and initial evaluation of a new strategy for 4D-MRI which is based on retrospective k-space reordering. Methods: We simulated a k-space reordered 4D-MRI on a 4D digital extended cardiac-torso (XCAT) human phantom. A 2D echo planar imaging MRI sequence [frame rate (F) = 0.448 Hz; image resolution (R) = 256 × 256; number of k-space segments (N KS ) = 4] with sequential image acquisition mode was assumed for the simulation. Image quality of the simulated “4D-MRI” acquired from the XCAT phantom was qualitatively evaluated, and tumor motion trajectories were compared to input signals. In particular, mean absolute amplitude differences (D) and cross correlation coefficients (CC) were calculated. Furthermore, to evaluate the data sufficient condition for the new 4D-MRI technique, a comprehensive simulation study was performed using 30 cancer patients’ respiratory profiles to study the relationships between data completeness (C p ) and a number of impacting factors: the number of repeated scans (N R ), number of slices (N S ), number of respiratory phase bins (N P ), N KS , F, R, and initial respiratory phase at image acquisition (P 0 ). As a proof-of-concept, we implemented the proposed k-space reordering 4D-MRI technique on a T2-weighted fast spin echo MR sequence and tested it on a healthy volunteer. Results: The simulated 4D-MRI acquired from the XCAT phantom matched closely to the original XCAT images. Tumor motion trajectories measured from the simulated 4D-MRI matched well with input signals (D = 0.83 and 0.83 mm, and CC = 0.998 and 0.992 in superior–inferior and anterior–posterior directions, respectively). The relationship between C p and N R was found best represented by an exponential function (C P =100(1−e −0.18N R ), when N S

Tumour control probability (TCP) for non-uniform activity distribution in radionuclide therapy

International Nuclear Information System (INIS)

Uusijaervi, Helena; Bernhardt, Peter; Forssell-Aronsson, Eva

2008-01-01

Non-uniform radionuclide distribution in tumours will lead to a non-uniform absorbed dose. The aim of this study was to investigate how tumour control probability (TCP) depends on the radionuclide distribution in the tumour, both macroscopically and at the subcellular level. The absorbed dose in the cell nuclei of tumours was calculated for 90 Y, 177 Lu, 103m Rh and 211 At. The radionuclides were uniformly distributed within the subcellular compartment and they were uniformly, normally or log-normally distributed among the cells in the tumour. When all cells contain the same amount of activity, the cumulated activities required for TCP = 0.99 (A-tilde TCP=0.99 ) were 1.5-2 and 2-3 times higher when the activity was distributed on the cell membrane compared to in the cell nucleus for 103m Rh and 211 At, respectively. TCP for 90 Y was not affected by different radionuclide distributions, whereas for 177 Lu, it was slightly affected when the radionuclide was in the nucleus. TCP for 103m Rh and 211 At were affected by different radionuclide distributions to a great extent when the radionuclides were in the cell nucleus and to lesser extents when the radionuclides were distributed on the cell membrane or in the cytoplasm. When the activity was distributed in the nucleus, A-tilde TCP=0.99 increased when the activity distribution became more heterogeneous for 103m Rh and 211 At, and the increase was large when the activity was normally distributed compared to log-normally distributed. When the activity was distributed on the cell membrane, A-tilde TCP=0.99 was not affected for 103m Rh and 211 At when the activity distribution became more heterogeneous. A-tilde TCP=0.99 for 90 Y and 177 Lu were not affected by different activity distributions, neither macroscopic nor subcellular

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

Science.gov (United States)

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.

LWD–TCP complex activates the morning gene CCA1 in Arabidopsis

Science.gov (United States)

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

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

Science.gov (United States)

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.

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

International Nuclear Information System (INIS)

Maurice, T.; Vignon, J.

1990-01-01

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) 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

OSI and TCP/IP

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Functional form comparison between the population and the individual Poisson based TCP models

International Nuclear Information System (INIS)

Schinkel, C.; Stavreva, N.; Stavrev, P.; Carlone, M.; Fallone, B.G.

2007-01-01

In this work, the functional form similarity between the individual and fundamental population TCP models is investigated. Using the fact that both models can be expressed in terms of the geometric parameters γ 50 and D 50 , we show that they have almost identical functional form for values of γ 50 ≥1. The conceptual inadequacy of applying an individual model to clinical data is also discussed. A general individual response TCP expression is given, parameterized by D f and γ f - the dose corresponding to a control level of f, and the normalized slope at that point. It is shown that the dose-response may be interpreted as an individual response only if γ 50 is sufficiently high. Based on the functional form equivalency between the individual and the population TCP models, we discuss the possibility of applying the individual TCP model for the case of heterogeneous irradiations. Due to the fact that the fundamental population TCP model is derived for homogeneous irradiations only, we propose the use of the EUD, given by the generalized mean dose, when the fundamental population TCP model is used to fit clinical data. (author)

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

Science.gov (United States)

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...

"De-Randomizing" Congestion Losses to Improve TCP Performance over Wired-Wireless Networks

National Research Council Canada - National Science Library

Biaz, Saad; Vaidya, Nitin H

2004-01-01

.... This paper proposes a simple biased queue management scheme that "de-randomizes" congestion losses and enables a TCP receiver to diagnose accurately the cause of a loss and inform the TCP sender to react appropriately...

BICLUSTERING METHODS FOR RE-ORDERING DATA MATRICES IN SYSTEMS BIOLOGY, DRUG DISCOVERY AND TOXICOLOGY

Directory of Open Access Journals (Sweden)

Christodoulos A. Floudas

2010-12-01

Full Text Available Biclustering has emerged as an important problem in the analysis of gene expression data since genes may only jointly respond over a subset of conditions. Many of the methods for biclustering, and clustering algorithms in general, utilize simplified models or heuristic strategies for identifying the ``best'' grouping of elements according to some metric and cluster definition and thus result in suboptimal clusters. In the first part of the presentation, we present a rigorous approach to biclustering, OREO, which is based on the Optimal RE-Ordering of the rows and columns of a data matrix so as to globally minimize the dissimilarity metric [1,2]. The physical permutations of the rows and columns of the data matrix can be modeled as either a network flow problem or a traveling salesman problem. The performance of OREO is tested on several important data matrices arising in systems biology to validate the ability of the proposed method and compare it to existing biclustering and clustering methods. In the second part of the talk, we will focus on novel methods for clustering of data matrices that are very sparse [3]. These types of data matrices arise in drug discovery where the x- and y-axis of a data matrix can correspond to different functional groups for two distinct substituent sites on a molecular scaffold. Each possible x and y pair corresponds to a single molecule which can be synthesized and tested for a certain property, such as percent inhibition of a protein function. For even moderate size matrices, synthesizing and testing a small fraction of the molecules is labor intensive and not economically feasible. Thus, it is of paramount importance to have a reliable method for guiding the synthesis process to select molecules that have a high probability of success. In the second part of the presentation, we introduce a new strategy to enable efficient substituent reordering and descriptor-free property estimation. Our approach casts

Static friction of porous bioceramic beta-TCP on intestinal mucus films.

Science.gov (United States)

Wang, Xin-Yu; Han, Ying-Chao; Jiang, Xin; Dai, Hong-Lian; Li, Shi-Pu

2006-09-01

The static friction behavior between a porous bioceramic material and an intestinal mucus film was investigated in order to develop a new intestine robotic endoscope. Here, the friction couple is porous beta-tricalcium phosphate (beta-TCP) and an artificial intestine mucus film. The effect of pore size of the beta-TCP material on the friction behavior is investigated. The results illustrated that in this friction system there is a relatively small normal force upon the intestinal mucus film of the intestine wall during locomotion. The maximum static friction force in this friction couple varies with the pore size of the porous beta-TCP material.

Static friction of porous bioceramic β-TCP on intestinal mucus films

International Nuclear Information System (INIS)

Wang Xinyu; Han Yingchao; Jiang Xin; Dai Honglian; Li Shipu

2006-01-01

The static friction behavior between a porous bioceramic material and an intestinal mucus film was investigated in order to develop a new intestine robotic endoscope. Here, the friction couple is porous β-tricalcium phosphate (β-TCP) and an artificial intestine mucus film. The effect of pore size of the β-TCP material on the friction behavior is investigated. The results illustrated that in this friction system there is a relatively small normal force upon the intestinal mucus film of the intestine wall during locomotion. The maximum static friction force in this friction couple varies with the pore size of the porous β-TCP material

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Analyzing the Effect of TCP and Server Population on Massively Multiplayer Games

Directory of Open Access Journals (Sweden)

Mirko Suznjevic

2014-01-01

Full Text Available Many Massively Multiplayer Online Role-Playing Games (MMORPGs use TCP flows for communication between the server and the game clients. The utilization of TCP, which was not initially designed for (soft real-time services, has many implications for the competing traffic flows. In this paper we present a series of studies which explore the competition between MMORPG and other traffic flows. For that aim, we first extend a source-based traffic model, based on player’s activities during the day, to also incorporate the impact of the number of players sharing a server (server population on network traffic. Based on real traffic traces, we statistically model the influence of the variation of the server’s player population on the network traffic, depending on the action categories (i.e., types of in-game player behaviour. Using the developed traffic model we prove that while server population only modifies specific action categories, this effect is significant enough to be observed on the overall traffic. We find that TCP Vegas is a good option for competing flows in order not to throttle the MMORPG flows and that TCP SACK is more respectful with game flows than other TCP variants, namely, Tahoe, Reno, and New Reno. Other tests show that MMORPG flows do not significantly reduce their sending window size when competing against UDP flows. Additionally, we study the effect of RTT unfairness between MMORPG flows, showing that it is less important than in the case of network-limited TCP flows.

Osteoconductivity and Biodegradability of Collagen Scaffold Coated with Nano-β-TCP and Fibroblast Growth Factor 2

Directory of Open Access Journals (Sweden)

Asako Ibara

2013-01-01

Full Text Available Nanoparticle bioceramics have become anticipated for biomedical applications. Highly bioactive and biodegradable scaffolds would be developed using nanoparticles of β-tricalcium phosphate (β-TCP. We prepared collagen scaffolds coated by nano-β-TCP and fibroblast growth factor 2 (FGF2 and evaluated the effects on new bone augmentation and biodegradation. The collagen sponge was coated with the nano-TCP dispersion and freeze-dried. Scaffold was characterized by SEM, TEM, XRD, compressive testing and cell seeding. Subsequently, the nano-β-TCP/collagen scaffold, collagen sponge, and each material loaded with FGF2 were implanted on rat cranial bone. As a control, no implantation was performed. Nano-TCP particles were found to be attached to the fibers of the collagen sponge by SEM and TEM observations. Scaffold coated with nano-TCP showed higher compressive strength and cytocompatibility. In histological evaluations at 10 days, inflammatory cells were rarely seen around the residual scaffold, suggesting that the nano-TCP material possesses good tissue compatibility. At 35 days, bone augmentation and scaffold degradation in histological samples receiving nano-β-TCP scaffold were significantly greater than those in the control. By loading of FGF2, advanced bone formation is facilitated, indicating that a combination with FGF2 would be effective for bone tissue engineering.

Active queue management controller design for TCP communication networks: Variable structure control approach

International Nuclear Information System (INIS)

Chen, C.-K.; Liao, T.-L.; Yan, J.-J.

2009-01-01

On the basis of variable structure control (VSC), an active queue management (AQM) controller is presented for a class of TCP communication networks. In the TCP/IP networks, the packet drop probability is limited between 0 and 1. Therefore, we modeled TCP/AQM as a rate-based non-linear system with a saturated input. The objective of the VSC-based AQM controller is to achieve the desired queue size and to guarantee the asymptotic stability of the closed-loop TCP non-linear system with saturated input. The performance and effectiveness of the proposed control law are then validated for different network scenarios through numerical simulations in both MATLAB and Network Simulator-2 (NS-2). Both sets of simulation results have confirmed that the proposed scheme outperforms other AQM schemes.

Active queue management controller design for TCP communication networks: Variable structure control approach

Energy Technology Data Exchange (ETDEWEB)

Chen, C.-K. [Department of Engineering Science, National Cheng Kung University, Tainan 701, Taiwan (China); Liao, T.-L. [Department of Engineering Science, National Cheng Kung University, Tainan 701, Taiwan (China)], E-mail: tlliao@mail.ncku.edu; Yan, J.-J. [Department of Computer and Communication, Shu-Te University, Kaohsiung 824, Taiwan (China)

2009-04-15

On the basis of variable structure control (VSC), an active queue management (AQM) controller is presented for a class of TCP communication networks. In the TCP/IP networks, the packet drop probability is limited between 0 and 1. Therefore, we modeled TCP/AQM as a rate-based non-linear system with a saturated input. The objective of the VSC-based AQM controller is to achieve the desired queue size and to guarantee the asymptotic stability of the closed-loop TCP non-linear system with saturated input. The performance and effectiveness of the proposed control law are then validated for different network scenarios through numerical simulations in both MATLAB and Network Simulator-2 (NS-2). Both sets of simulation results have confirmed that the proposed scheme outperforms other AQM schemes.

Identification of two combined genes responsible for dechlorination of 3,5,6-trichloro-2-pyridinol (TCP) in Cupriavidus pauculus P2.

Science.gov (United States)

Cao, Li; Xu, Jianhong; Wu, Guang; Li, Mingxing; Jiang, Jiandong; He, Jian; Li, Shunpeng; Hong, Qing

2013-09-15

Dehalogenation is an important mechanism for degrading and detoxifying halogenated aromatics in microbes. However, the biochemical and molecular mechanisms of dehalogenation of 3,5,6-trichloro-2-pyridinol (TCP) are still unknown. In this study, a novel 6012 bp gene cluster was cloned from TCP-degrading strain P2, which was responsible for the dehalogenation of TCP. The cluster included a monooxygenase gene (tcpA1), a flavin reductase gene (tcpB1), tcpR1, orf1 and orf2. TcpA1 and TcpB1 were indispensable for the dehalogenation of TCP. They worked together to catalyze the dehalogenation of three chlorine of TCP, and generated a more readily biodegradable product of 3,6-dihydroxypyridine-2,5-dione. TcpA1 displayed the highest activity against TCP at 40°C and at pH 8.0. Cu(2+), Zn(2+), and Hg(2+) significantly inhibited enzyme activity. To the best of our knowledge, this is the first report on a gene cluster responsible for TCP degradation. Copyright © 2013 Elsevier B.V. All rights reserved.

Robustness of Multiple High Speed TCP CUBIC Connections Under Severe Operating Conditions

DEFF Research Database (Denmark)

Pilimon, Artur; Ruepp, Sarah Renée; Berger, Michael Stübert

2015-01-01

We study the adaptation capabilities and robustness of the high-speed TCP CUBIC algorithm. For this purpose we consider a network environment with variable and high random packet loss and a large Bandwidth-Delay product, shared by multiple heterogeneous TCP connections. The analysis is based on a...

TCP/IP Communication System for Controlling a Vehicular Traffic Intersection

Directory of Open Access Journals (Sweden)

Pedraza-Martínez Luis Fernando

2013-10-01

Full Text Available This paper describes the development of a prototype of a vehicular traffic controller, whose system of communication is based on the TCP/IP protocol, in order to re- motely monitor and control the operation of traffic lights for a vehicular intersection. The results show the times of communication between the central and the traffic controller. The conclusions highlight the importance of using the TCP/IP protocol in traffic light systems.

TCP (truncated compound Poisson) process for multiplicity distributions in high energy collisions

International Nuclear Information System (INIS)

Srivastave, P.P.

1990-01-01

On using the Poisson distribution truncated at zero for intermediate cluster decay in a compound Poisson process, the authors obtain TCP distribution which describes quite well the multiplicity distributions in high energy collisions. A detailed comparison is made between TCP and NB for UA5 data. The reduced moments up to the fifth agree very well with the observed ones. The TCP curves are narrower than NB at high multiplicity tail, look narrower at very high energy and develop shoulders and oscillations which become increasingly pronounced as the energy grows. At lower energies the distributions, of the data for fixed intervals of rapidity for UA5 data and for the data (at low energy) for e + e - annihilation and pion-proton, proton-proton and muon-proton scattering. A discussion of compound Poisson distribution, expression of reduced moments and Poisson transforms are also given. The TCP curves and curves of the reduced moments for different values of the parameters are also presented

The Arabidopsis Transcription Factor AtTCP15 Regulates Endoreduplication by Modulating Expression of Key Cell-cycle Genes

Institute of Scientific and Technical Information of China (English)

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

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.

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

International Nuclear Information System (INIS)

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

2011-01-01

Highlights: → TCP4 is a class II TCP transcription factor, that represses cell division in Arabidopsis. → TCP4 expression in yeast retards cell division by blocking G1 → S transition. → 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, 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.

A new method in prediction of TCP phases formation in superalloys

International Nuclear Information System (INIS)

Mousavi Anijdan, S.H.; Bahrami, A.

2005-01-01

The purpose of this investigation is to develop a model for prediction of topologically closed-packed (TCP) phases formation in superalloys. In this study, artificial neural networks (ANN), using several different network architectures, were used to investigate the complex relationships between TCP phases and chemical composition of superalloys. In order to develop an optimum ANN structure, more than 200 experimental data were used to train and test the neural network. The results of this investigation shows that a multilayer perceptron (MLP) form of the neural networks with one hidden layer and 10 nodes in the hidden layer has the lowest mean absolute error (MAE) and can be accurately used to predict the electron-hole number (N v ) and TCP phases formation in superalloys

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

Science.gov (United States)

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.

{beta}-TCP porous pellets as an orthopaedic drug delivery system: ibuprofen/carrier physicochemical interactions

Energy Technology Data Exchange (ETDEWEB)

Baradari, Hiba; Damia, Chantal; Dutreih-Colas, Maggy; Champion, Eric; Chulia, Dominique; Viana, Marylene, E-mail: hiva.baradari@etu.unilim.fr [SPCTS-Centre Europeen de la Ceramique, 12 Rue Atlantis, 87068 Limoges CEDEX (France)

2011-10-15

Calcium phosphate bone substitute materials can be loaded with active substances for in situ, targeted drug administration. In this study, porous {beta}-TCP pellets were investigated as an anti-inflammatory drug carrier. Porous {beta}-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 {beta}-TCP is weak. The physicochemical characterizations of loaded pellets confirmed that the reversible physisorption of ibuprofen on {beta}-TCP pellets is due to Van der Waals forces, and this property was associated with the 100% ibuprofen release.

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

International Nuclear Information System (INIS)

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

2011-01-01

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.

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

Science.gov (United States)

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.

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

International Nuclear Information System (INIS)

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

2015-01-01

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. (paper)

On TCP-based Session Initiation Protocol (SIP) Server Overload Control

OpenAIRE

Shen, Charles; Schulzrinne, Henning

2010-01-01

The Session Initiation Protocol (SIP) server overload management has attracted interest since SIP is being widely deployed in the Next Generation Networks (NGN) as a core signaling protocol. Yet all existing SIP overload control work is focused on SIP-over-UDP, despite the fact that TCP is increasingly seen as the more viable choice of SIP transport. This paper answers the following questions: is the existing TCP flow control capable of handling the SIP overload problem? If not, why and how c...

TCP-Call Admission Control Interaction in Multiplatform Space Architectures

Directory of Open Access Journals (Sweden)

Georgios Theodoridis

2007-06-01

Full Text Available The implementation of efficient call admission control (CAC algorithms is useful to prevent congestion and guarantee target quality of service (QoS. When TCP protocol is adopted, some inefficiencies can arise due to the peculiar evolution of the congestion window. The development of cross-layer techniques can greatly help to improve efficiency and flexibility for wireless networks. In this frame, the present paper addresses the introduction of TCP feedback into the CAC procedures in different nonterrestrial wireless architectures. CAC performance improvement is shown for different space-based architectures, including both satellites and high altitude platform (HAP systems.

TCP-Call Admission Control Interaction in Multiplatform Space Architectures

Directory of Open Access Journals (Sweden)

Roseti Cesare

2007-01-01

Full Text Available The implementation of efficient call admission control (CAC algorithms is useful to prevent congestion and guarantee target quality of service (QoS. When TCP protocol is adopted, some inefficiencies can arise due to the peculiar evolution of the congestion window. The development of cross-layer techniques can greatly help to improve efficiency and flexibility for wireless networks. In this frame, the present paper addresses the introduction of TCP feedback into the CAC procedures in different nonterrestrial wireless architectures. CAC performance improvement is shown for different space-based architectures, including both satellites and high altitude platform (HAP systems.

Study of TCP densification via image analysis

International Nuclear Information System (INIS)

Silva, R.C.; Alencastro, F.S.; Oliveira, R.N.; Soares, G.A.

2011-01-01

Among ceramic materials that mimic human bone, β-type tri-calcium phosphate (β-TCP) has shown appropriate chemical stability and superior resorption rate when compared to hydroxyapatite. In order to increase its mechanical strength, the material is sintered, under controlled time and temperature conditions, to obtain densification without phase change. In the present work, tablets were produced via uniaxial compression and then sintered at 1150°C for 2h. The analysis via XRD and FTIR showed that the sintered tablets were composed only by β-TCP. The SEM images were used for quantification of grain size and volume fraction of pores, via digital image analysis. The tablets showed small pore fraction (between 0,67% and 6,38%) and homogeneous grain size distribution (∼2μm). Therefore, the analysis method seems viable to quantify porosity and grain size. (author)

Parallel deposition, sorting, and reordering methods in the Hybrid Ordered Plasma Simulation (HOPS) code

International Nuclear Information System (INIS)

Anderson, D.V.; Shumaker, D.E.

1993-01-01

From a computational standpoint, particle simulation calculations for plasmas have not adapted well to the transitions from scalar to vector processing nor from serial to parallel environments. They have suffered from inordinate and excessive accessing of computer memory and have been hobbled by relatively inefficient gather-scatter constructs resulting from the use of indirect indexing. Lastly, the many-to-one mapping characteristic of the deposition phase has made it difficult to perform this in parallel. The authors' code sorts and reorders the particles in a spatial order. This allows them to greatly reduce the memory references, to run in directly indexed vector mode, and to employ domain decomposition to achieve parallelization. In this hybrid simulation the electrons are modeled as a fluid and the field equations solved are obtained from the electron momentum equation together with the pre-Maxwell equations (displacement current neglected). Either zero or finite electron mass can be used in the electron model. The resulting field equations are solved with an iteratively explicit procedure which is thus trivial to parallelize. Likewise, the field interpolations and the particle pushing is simple to parallelize. The deposition, sorting, and reordering phases are less simple and it is for these that the authors present detailed algorithms. They have now successfully tested the parallel version of HOPS in serial mode and it is now being readied for parallel execution on the Cray C-90. They will then port HOPS to a massively parallel computer, in the next year

Analysis of CBRP for UDP and TCP Traffic-Classes to measure throughput in MANETs

Directory of Open Access Journals (Sweden)

Hardeep Singh Rayait

2013-01-01

Full Text Available In this paper, we analyse the throughput of both TCP and UDP traffic classes for cluster based routing protocol for mobile ad hoc network. It uses clustering structure to improve throughput , decrease average end-to-end delay and improve the average packet delivery ratio. We simulate our routing protocol for nodes running the IEEE802.11 MAC for analysis of throughput for both UDP and TCP traffic classes. The application layer protocol used for UDP is CBR and for TCP is FTP.

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

Directory of Open Access Journals (Sweden)

Chengde Gao

2015-03-01

Full Text Available 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.

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

Science.gov (United States)

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 (pPRP+TCP groups (pPRP+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 (pPRP+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.

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

Science.gov (United States)

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.

A transport layer protocol for the future high speed grid computing: SCTP versus fast tcp multihoming

International Nuclear Information System (INIS)

Arshad, M.J.; Mian, M.S.

2010-01-01

TCP (Transmission Control Protocol) is designed for reliable data transfer on the global Internet today. One of its strong points is its use of flow control algorithm that allows TCP to adjust its congestion window if network congestion is occurred. A number of studies and investigations have confirmed that traditional TCP is not suitable for each and every type of application, for example, bulk data transfer over high speed long distance networks. TCP sustained the time of low-capacity and short-delay networks, however, for numerous factors it cannot be capable to efficiently deal with today's growing technologies (such as wide area Grid computing and optical-fiber networks). This research work surveys the congestion control mechanism of transport protocols, and addresses the different issues involved for transferring the huge data over the future high speed Grid computing and optical-fiber networks. This work also presents the simulations to compare the performance of FAST TCP multihoming with SCTP (Stream Control Transmission Protocol) multihoming in high speed networks. These simulation results show that FAST TCP multihoming achieves bandwidth aggregation efficiently and outperforms SCTP multihoming under a similar network conditions. The survey and simulation results presented in this work reveal that multihoming support into FAST TCP does provide a lot of benefits like redundancy, load-sharing and policy-based routing, which largely improves the whole performance of a network and can meet the increasing demand of the future high-speed network infrastructures (such as in Grid computing). (author)

Evaluation of TCP Congestion Control Algorithms on the Windows Vista Platform

Energy Technology Data Exchange (ETDEWEB)

Li, Yee-Ting; /SLAC

2006-07-07

CTCP, an innovative TCP congestion control algorithm developed by Microsoft, is evaluated and compared to HSTCP and StandardTCP. Tests were performed on the production Internet from Stanford Linear Accelerator Center (SLAC) to various geographically located hosts to give a broad overview of the performances. We find that certain issues were apparent during testing (not directly related to the congestion control algorithms) which may skew results. With this in mind, we find that CTCP performed similarly to HSTCP across a multitude of different network environments. However, to improve the fairness and to reduce the impact of CTCP upon existing StandardTCP traffic, two areas of further research were investigated. Algorithmic additions to CTCP for burst control to reduce the aggressiveness of its cwnd increments demonstrated beneficial improvements in both fairness and throughput over the original CTCP algorithm. Similarly, {gamma} auto-tuning algorithms were investigated to dynamically adapt CTCP flows to their network conditions for optimal performance. While the effects of these auto-tuning algorithms when used in addition to burst control showed little to no benefit to fairness nor throughput for the limited number of network paths tested, one of the auto-tuning algorithms performed such that there was negligible impact upon StandardTCP. With these improvements, CTCP was found to perform better than HSTCP in terms of fairness and similarly in terms of throughput under the production environments tested.

Evaluation of TCP Congestion Control Algorithms on the Windows Vista Platform

International Nuclear Information System (INIS)

Li, Y

2006-01-01

CTCP, an innovative TCP congestion control algorithm developed by Microsoft, is evaluated and compared to HSTCP and StandardTCP. Tests were performed on the production Internet from Stanford Linear Accelerator Center (SLAC) to various geographically located hosts to give a broad overview of the performances. We find that certain issues were apparent during testing (not directly related to the congestion control algorithms) which may skew results. With this in mind, we find that CTCP performed similarly to HSTCP across a multitude of different network environments. However, to improve the fairness and to reduce the impact of CTCP upon existing StandardTCP traffic, two areas of further research were investigated. Algorithmic additions to CTCP for burst control to reduce the aggressiveness of its cwnd increments demonstrated beneficial improvements in both fairness and throughput over the original CTCP algorithm. Similarly, auto-tuning algorithms were investigated to dynamically adapt CTCP flows to their network conditions for optimal performance. Whilst the effects of these auto-tuning algorithms when used in addition to burst control showed little to no benefit to fairness nor throughput for the limited number of network paths tested, one of the auto-tuning algorithms performed such that there was negligible impact upon StandardTCP. With these improvements, CTCP was found to perform better than HSTCP in terms of fairness and similarly in terms of throughput under the production environments tested

Cascade Probability Control to Mitigate Bufferbloat under Multiple Real-World TCP Stacks

Directory of Open Access Journals (Sweden)

Hoang-Linh To

2015-01-01

Full Text Available Persistently full buffer problem, commonly known as bufferbloat, causes unnecessary additional latency and throughput degradation whenever congestion happens in Internet. Several proposed queue management schemes, with the debloat mission, are almost based on the modification of one-loop feedback control where the instability and bad transient behavior are still big challenges. In this paper, we present a cascade probability control scheme using margin optimal method to address such challenges under different kinds of real-world TCP stacks. Simulation results guarantee the measured round trip time tracking to a low value of delay (e.g., ≈180 ms under TCP Reno, and ≈130 ms under TCP Cubic and ≈50% delay reduction in comparison to current deployed queue management schemes in network devices.

Enhanced Critical Size Defect Repair in Rabbit Mandible by Electrospun Gelatin/β-TCP Composite Nanofibrous Membranes

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Mingming Xu

2015-01-01

Full Text Available The design and fabrication of biodegradable barrier membranes with satisfactory structure and composition remain a considerable challenge for periodontal tissue regeneration. We have developed a biomimetic nanofibrous membrane made from a composite of gelatin and β-tricalcium phosphate (β-TCP. We previously confirmed the in vitro biological performance of the membrane material, but the efficacy of the membranes in promoting bone repair in situ has not yet been examined. Gelatin/β-TCP composite nanofibers were fabricated by incorporation of 20 wt.% β-TCP nanoparticles into electrospun gelatin nanofibers. Electron microscopy showed that the composite membranes presented a nonwoven structure with an interconnected porous network and had a rough surface due to the β-TCP nanoparticles, which were distributed widely and uniformly throughout the gelatin-fiber matrix. The repair efficacy of rabbit mandible defects implanted with bone substitute (Bio-Oss and covered with the gelatin/β-TCP composite nanofibrous membrane was evaluated in comparison with pure gelatin nanofibrous membrane. Gross observation, histological examination, and immunohistochemical analysis showed that new bone formation and defect closure were significantly enhanced by the composite membranes compared to the pure gelatin ones. From these results, we conclude that nanofibrous gelatin/β-TCP composite membranes could serve as effective barrier membranes for guided tissue regeneration.

TCP/IP Network Administration

CERN Document Server

Hunt, Craig

2002-01-01

This complete guide to setting up and running a TCP/IP network is essential for network administrators, and invaluable for users of home systems that access the Internet. The book starts with the fundamentals -- what protocols do and how they work, how addresses and routing are used to move data through the network, how to set up your network connection -- and then covers, in detail, everything you need to know to exchange information via the Internet. Included are discussions on advanced routing protocols (RIPv2, OSPF, and BGP) and the gated software package that implements them, a tutorial

Combining phylogenetic and syntenic analyses for understanding the evolution of TCP ECE genes in eudicots.

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Hélène L Citerne

Full Text Available 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 Solanumlycopersicum 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 Aquilegiacoerulea and Nelumbonucifera 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.

ComboCoding: Combined intra-/inter-flow network coding for TCP over disruptive MANETs

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Chien-Chia Chen

2011-07-01

Full Text Available TCP over wireless networks is challenging due to random losses and ACK interference. Although network coding schemes have been proposed to improve TCP robustness against extreme random losses, a critical problem still remains of DATA–ACK interference. To address this issue, we use inter-flow coding between DATA and ACK to reduce the number of transmissions among nodes. In addition, we also utilize a “pipeline” random linear coding scheme with adaptive redundancy to overcome high packet loss over unreliable links. The resulting coding scheme, ComboCoding, combines intra-flow and inter-flow coding to provide robust TCP transmission in disruptive wireless networks. The main contributions of our scheme are twofold; the efficient combination of random linear coding and XOR coding on bi-directional streams (DATA and ACK, and the novel redundancy control scheme that adapts to time-varying and space-varying link loss. The adaptive ComboCoding was tested on a variable hop string topology with unstable links and on a multipath MANET with dynamic topology. Simulation results show that TCP with ComboCoding delivers higher throughput than with other coding options in high loss and mobile scenarios, while introducing minimal overhead in normal operation.

MICROCT AND PREPARATION OF ß-TCP GRANULAR MATERIAL BY THE POLYURETHANE FOAM METHOD

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Robert Filmon

2011-05-01

Full Text Available Commercial ß-tricalcium phosphate (ß-TCP is commercialy available in granules manufactured by sintering of powders. We have evaluated the different steps of the manufacturing process of ß-TCP ceramics granules prepared from blocks obtained with the polyurethane foam technology. Three types of slurry were prepared with 10, 15 and 25 g of ß-TCP per gram of polyurethane foam. Analysis was done by scanning electron microscopy, EDX, Raman spectroscopy and microcomputed tomography combined with image analysis. A special algorithm was used to identify the internal microporosity (created by the calcination of the foam from the internal macroporosity due to the spatial repartition of the material. The low ß-TCP dosages readily infiltrated the foam and the slurry was deposited along the polymer rods. On the contrary, the highest concentration produced inhomogeneous infiltrated blocks and foam cavities appeared completely filled in some areas. 2D microcomputed sections and reconstructed 3D models evidenced this phenomenon and the frequency distribution of the thickness and separation of material trabeculae confirmed the heterogeneity of the distribution. When crushed, blocks prepared with the 25 g slurry provided the largest and irregular granulates.

Centrically reordered inversion recovery half-Fourier single-shot turbo spin-echo sequence: improvement of the image quality of oxygen-enhanced MRI

International Nuclear Information System (INIS)

Ohno, Yoshiharu; Hatabu, Hiroto; Higashino, Takanori; Kawamitsu, Hideaki; Watanabe, Hirokazu; Takenaka, Daisuke; Cauteren, Marc van; Sugimura, Kazuro

2004-01-01

Purpose: The purpose of the study presented here was to determine the improvement in image quality of oxygen-enhanced magnetic resonance (MR) subtraction imaging obtained with a centrically reordered inversion recovery half-Fourier single-shot turbo spin-echo (c-IR-HASTE) sequence compared with that obtained with a conventional sequentially reordered inversion recovery single-shot HASTE (s-IR-HASTE) sequence for pulmonary imaging. Materials and methods: Oxygen-enhanced MR imaging using a 1.5 T whole body scanner was performed on 12 healthy, non-smoking volunteers. Oxygen-enhanced MR images were obtained with the coronal two-dimensional (2D) c-IR-HASTE sequence and 2D s-IR-HASTE sequence combined with respiratory triggering. For a 256x256 matrix, 132 phase-encoding steps were acquired including four steps for phase correction. Inter-echo spacing for each sequence was 4.0 ms. The effective echo time (TE) for c-IR-HASTE was 4.0 ms, and 16 ms for s-IR-HASTE. The inversion time (TI) was 900 ms. To determine the improvement in oxygen-enhanced MR subtraction imaging by c-IR-HASTE, CNRs of subtraction image, overall image quality, and image degradation of the c-IR-HASTE and s-IR-HASTE techniques were statistically compared. Results: CNR, overall image quality, and image degradation of c-IR-HASTE images showed significant improvement compared to those s-IR-HASTE images (P<0.05). Conclusion: Centrically reordered inversion recovery half-Fourier single-shot turbo spin-echo (c-IR-HASTE) sequence enhanced the signal from the lung and improved the image quality of oxygen-enhanced MR subtraction imaging

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

Science.gov (United States)

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.

A Cross Layer Solution to Address TCP Intra-flow Performance Degradation in Multihop Ad hoc Networks

OpenAIRE

Rakocevic, V.; Hamadani, E.

2008-01-01

Incorporating the concept of TCP end-to-end congestion control for wireless networks is one of the primary concerns in designing ad hoc networks since TCP was primarily designed and optimized based on the assumptions for wired networks. In this study, our interest lies on tackling the TCP instability and in particular intra-flow instability problem since due to the nature of applications in multihop ad hoc networks, connection instability or starvation even for a short period of time can have...

Design of feedback controller for TCP/AQM networks

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Sukant Kishoro Bisoy

2017-02-01

Full Text Available In this paper, we propose a novel proportional-differential-type feedback controller called Novel-PD as new active queue management (AQM to regulate the queue length with small oscillation. It measures the current queue length and uses the current queue length and differential error signals to adjust packet drop probability dynamically. We provide control theoretic analysis of system stability and develop guidelines to select control gain parameters of Novel-PD. The design of Novel-PD for TCP/AQM system is given in details. NS2 is used for conducting extensive simulation. The proposed controller is compared with random early detection (RED, random exponential marking (REM, proportional integrator (PI and proportional derivative (PD controller. Result shows that, Novel-PD is stable and achieves faster response in dynamic environments where number of TCP connections, bottleneck capacity, round trip time (RTT keeps changing. The proposed controller outperforms other AQM schemes.

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

Science.gov (United States)

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.

Synthesis of 3-[18F]-fluoromethyl-TCP1, a potential tool for PET study of the NMDA receptor channel complex

International Nuclear Information System (INIS)

Ponchant, M.; Crouzel, C.

1992-01-01

In an attempt to visualize the NMDA glutamatergic receptors and after checking the biological activity of the cold 3-fluoromethyl-TCP, 3-[ 18 F]-fluoro-methyl-TCP was synthesized by a nucleophilic substitution of 3-bromomethyl-TCP with [ 18 F - ]. (author)

Tricalcium phosphate/hydroxyapatite (TCP-HA) bone scaffold as potential candidate for the formation of tissue engineered bone.

Science.gov (United States)

Sulaiman, Shamsul Bin; Keong, Tan Kok; Cheng, Chen Hui; Saim, Aminuddin Bin; Idrus, Ruszymah Bt Hj

2013-06-01

Various materials have been used as scaffolds to suit different demands in tissue engineering. One of the most important criteria is that the scaffold must be biocompatible. This study was carried out to investigate the potential of HA or TCP/HA scaffold seeded with osteogenic induced sheep marrow cells (SMCs) for bone tissue engineering. HA-SMC and TCP/HA-SMC constructs were induced in the osteogenic medium for three weeks prior to implantation in nude mice. The HA-SMC and TCP/HA-SMC constructs were implanted subcutaneously on the dorsum of nude mice on each side of the midline. These constructs were harvested after 8 wk of implantation. Constructs before and after implantation were analyzed through histological staining, scanning electron microscope (SEM) and gene expression analysis. The HA-SMC constructs demonstrated minimal bone formation. TCP/HA-SMC construct showed bone formation eight weeks after implantation. The bone formation started on the surface of the ceramic and proceeded to the centre of the pores. H&E and Alizarin Red staining demonstrated new bone tissue. Gene expression of collagen type 1 increased significantly for both constructs, but more superior for TCP/HA-SMC. SEM results showed the formation of thick collagen fibers encapsulating TCP/HA-SMC more than HA-SMC. Cells attached to both constructs surface proliferated and secreted collagen fibers. The findings suggest that TCP/HA-SMC constructs with better osteogenic potential compared to HA-SMC constructs can be a potential candidate for the formation of tissue engineered bone.

Influence of different naf concentration on the mechanical and morphological properties on sintered β-TCP

International Nuclear Information System (INIS)

Saito, L.; Cardoso, H.A.I.; Zavaglia, C.A.C.; Motisuke, M.

2011-01-01

Among the bioceramics, [beta]-tricalcium phosphate, β-TCP, is currently used in biomedical applications due to its in vivo reabsorption and chemical composition, important for bone formation and repair. Researchers showed that the addition of sodium fluoride (NaF) up to 2wt.% increases β-TCP mechanical properties without altering its biocompatibility and bioactivity. In this work, the effect of different NaF concentrations (2wt.% to 5wt.%) on β-TCP properties was studied. The samples were sintered at 1250 deg C during four hours. Afterwards, it were determined its mechanical resistance, density, morphology and chemical composition as a function of NaF content. The results showed that the presence of NaF does not lead to an increase on the mechanical properties. This fact is probably related to the formation of a mixture of TCP, apatite and sodium and calcium phosphates; and a visible increase on samples' density.(author)

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

Science.gov (United States)

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.

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

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Junjie Guan

Full Text Available 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.

Specific proliferation rates of human osteoblasts on calcium phosphate surfaces with variable concentrations of α-TCP

International Nuclear Information System (INIS)

Santos, Euler A. dos; Farina, Marcos; Soares, Gloria A.

2007-01-01

Ideally, ceramics used in the repair of bone defects need to be resorbed and replaced by newly formed bone in vivo. Tricalcium phosphate (TCP) has been widely used in association with hydroxyapatite (HA) due to its higher resorption kinetics when compared with HA alone. The aim of our study was to quantitatively investigate the effect of α-tricalcium phosphate (α-TCP) on human osteoblasts' adhesion and proliferation. Ceramic samples with variable concentrations of α-TCP and HA were produced by the calcination of calcium-deficient and stoichiometric HA. Human osteoblasts were cultured on the materials in three distinct experiments with different concentrations of cells. Numerical evaluation of cellular growth along time in culture was performed for each condition. The quantity of cells seeded onto the ceramics seems to influence the osteoblast behavior once proliferation was lower when more cells were seeded onto the samples. However, a smaller content of α-TCP in relation to that of HA did not significantly modify the specific proliferation rates of the osteoblasts. Only after a long time in culture, the increasing of the α-TCP content seems to change the cells' behavior

A TCP/IP transport layer for the DAQ of the CMS experiment

International Nuclear Information System (INIS)

Kozlovszky, M.

2004-01-01

The CMS collaboration is currently investigating various networking technologies that may meet the requirements of the CMS Data Acquisition System (DAQ). During this study, a peer transport component based on TCP/IP has been developed using object-oriented techniques for the distributed DAQ framework named XDAQ. This framework has been designed to facilitate the development of distributed data acquisition systems within the CMS Experiment. The peer transport component has to meet 3 main requirements. Firstly, it had to provide fair access to the communication medium for competing applications. Secondly, it had to provide as much of the available bandwidth to the application layer as possible. Finally, it had to hide the complexity of using non-blocking TCP/IP connections from the application layer. This paper describes the development of the peer transport component and then presents and draws conclusions on the measurements made during tests. The major topics investigated include: blocking versus non-blocking communication, TCP/IP configuration options, multi-rail connections

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

Science.gov (United States)

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.

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

Energy Technology Data Exchange (ETDEWEB)

Ardjomandi, N.; Huth, J. [Department of Oral and Maxillofacial Surgery, University Hospital Tübingen (Germany); Stamov, D.R. [JPK Instruments AG, Berlin (Germany); Henrich, A. [Department of Oral and Maxillofacial Surgery, University Hospital Tübingen (Germany); Klein, C. [Dental Practice Zahngesundheit Waiblingen, Waiblingen (Germany); Wendel, H.-P. [Department of Thoracic, Cardiac and Vascular Surgery, University Hospital, Tübingen (Germany); Reinert, S. [Department of Oral and Maxillofacial Surgery, University Hospital Tübingen (Germany); Alexander, D., E-mail: dorothea.alexander@med.uni-tuebingen.de [Department of Oral and Maxillofacial Surgery, University Hospital Tübingen (Germany)

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. - Highlights: • Covalent binding of aptamer 74 on PLGA-coated β-tricalcium phosphate constructs. • AFM analysis of rupture forces between aptamer 74 and jaw periosteal cells. • Analysis of jaw periosteal cell functions on aptamer coated β-TCP constructs.

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

International Nuclear Information System (INIS)

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

2016-01-01

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. - Highlights: • Covalent binding of aptamer 74 on PLGA-coated β-tricalcium phosphate constructs. • AFM analysis of rupture forces between aptamer 74 and jaw periosteal cells. • Analysis of jaw periosteal cell functions on aptamer coated β-TCP constructs.

Geometrical versus Random β-TCP Scaffolds: Exploring the Effects on Schwann Cell Growth and Behavior.

Directory of Open Access Journals (Sweden)

Lauren Sweet

Full Text Available Numerous studies have demonstrated that Schwann cells (SCs play a role in nerve regeneration; however, their role in innervating a bioceramic scaffold for potential application in bone regeneration is still unknown. Here we report the cell growth and functional behavior of SCs on β-tricalcium phosphate (β-TCP scaffolds arranged in 3D printed-lattice (P-β-TCP and randomly-porous, template-casted (N-β-TCP structures. Our results indicate that SCs proliferated well and expressed the phenotypic markers p75LNGFR and the S100-β subunit of SCs as well as displayed growth morphology on both scaffolds, but SCs showed spindle-shaped morphology with a significant degree of SCs alignment on the P-β-TCP scaffolds, seen to a lesser degree in the N-β-TCP scaffold. The gene expressions of nerve growth factor (β-ngf, neutrophin-3 (nt-3, platelet-derived growth factor (pdgf-bb, and vascular endothelial growth factor (vegf-a were higher at day 7 than at day 14. While no significant differences in protein secretion were measured between these last two time points, the scaffolds promoted the protein secretion at day 3 compared to that on the cell culture plates. These results together imply that the β-TCP scaffolds can support SC cell growth and that the 3D-printed scaffold appeared to significantly promote the alignment of SCs along the struts. Further studies are needed to investigate the early and late stage relationship between gene expression and protein secretion of SCs on the scaffolds with refined characteristics, thus better exploring the potential of SCs to support vascularization and innervation in synthetic bone grafts.

Improving TCP Performance over Wireless Ad Hoc Networks with Busy Tone Assisted Scheme

Directory of Open Access Journals (Sweden)

Cai Lin

2006-01-01

Full Text Available It is well known that transmission control protocol (TCP performance degrades severely in IEEE 802.11-based wireless ad hoc networks. We first identify two critical issues leading to the TCP performance degradation: (1 unreliable broadcast, since broadcast frames are transmitted without the request-to-send and clear-to-send (RTS/CTS dialog and Data/ACK handshake, so they are vulnerable to the hidden terminal problem; and (2 false link failure which occurs when a node cannot successfully transmit data temporarily due to medium contention. We then propose a scheme to use a narrow-bandwidth, out-of-band busy tone channel to make reservation for broadcast and link error detection frames only. The proposed scheme is simple and power efficient, because only the sender needs to transmit two short messages in the busy tone channel before sending broadcast or link error detection frames in the data channel. Analytical results show that the proposed scheme can dramatically reduce the collision probability of broadcast and link error detection frames. Extensive simulations with different network topologies further demonstrate that the proposed scheme can improve TCP throughput by 23% to 150%, depending on user mobility, and effectively enhance both short-term and long-term fairness among coexisting TCP flows in multihop wireless ad hoc networks.

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

Science.gov (United States)

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.

The battle between standards: TCP/IP vs OSI victory through path dependency or by quality?

NARCIS (Netherlands)

Maathuis, Ivo; Smit, Willem A.; Egyedi, T.M.; Krechmer, K.; Jakobs, K.

2003-01-01

Between the end of the 1970s and 1994 a fierce competition existed between two possible standards, TCP/IP and OSI, to solve the problem of interoperability of computer networks. Around 1994 it became evident that TCP/IP and not OSI had become the dominant standard. We specifically deal with the

SET: Session Layer-Assisted Efficient TCP Management Architecture for 6LoWPAN with Multiple Gateways

Directory of Open Access Journals (Sweden)

Akbar AliHammad

2010-01-01

Full Text Available 6LoWPAN (IPv6 based Low-Power Personal Area Network is a protocol specification that facilitates communication of IPv6 packets on top of IEEE 802.15.4 so that Internet and wireless sensor networks can be inter-connected. This interconnection is especially required in commercial and enterprise applications of sensor networks where reliable and timely data transfers such as multiple code updates are needed from Internet nodes to sensor nodes. For this type of inbound traffic which is mostly bulk, TCP as transport layer protocol is essential, resulting in end-to-end TCP session through a default gateway. In this scenario, a single gateway tends to become the bottleneck because of non-uniform connectivity to all the sensor nodes besides being vulnerable to buffer overflow. We propose SET; a management architecture for multiple split-TCP sessions across a number of serving gateways. SET implements striping and multiple TCP session management through a shim at session layer. Through analytical modeling and ns2 simulations, we show that our proposed architecture optimizes communication for ingress bulk data transfer while providing associated load balancing services. We conclude that multiple split-TCP sessions managed in parallel across a number of gateways result in reduced latency for bulk data transfer and provide robustness against gateway failures.

MPTCP Tunnel: An Architecture for Aggregating Bandwidth of Heterogeneous Access Networks

Directory of Open Access Journals (Sweden)

Xiaolan Liu

2018-01-01

Full Text Available Fixed and cellular networks are two typical access networks provided by operators. Fixed access network is widely employed; nevertheless, its bandwidth is sometimes not sufficient enough to meet user bandwidth requirements. Meanwhile, cellular access network owns unique advantages of wider coverage, faster increasing link speed, more flexible deployment, and so forth. Therefore, it is attractive for operators to mitigate the bandwidth shortage by bundling these two. Actually, there have been existing schemes proposed to aggregate the bandwidth of two access networks, whereas they all have their own problems, like packet reordering or extra latency overhead. To address this problem, we design new architecture, MPTCP Tunnel, to aggregate the bandwidth of multiple heterogeneous access networks from the perspective of operators. MPTCP Tunnel uses MPTCP, which solves the reordering problem essentially, to bundle multiple access networks. Besides, MPTCP Tunnel sets up only one MPTCP connection at play which adapts itself to multiple traffic types and TCP flows. Furthermore, MPTCP Tunnel forwards intact IP packets through access networks, maintaining the end-to-end TCP semantics. Experimental results manifest that MPTCP Tunnel can efficiently aggregate the bandwidth of multiple access networks and is more adaptable to the increasing heterogeneity of access networks than existing mechanisms.

Determination of physical properties for β-TCP + chitosan biomaterial obtained on metallic 316L substrates

International Nuclear Information System (INIS)

Mina, A.; Castaño, A.; Caicedo, J.C.; Caicedo, H.H.; Aguilar, Y.

2015-01-01

Material surface modification, particularly the deposition of special coatings on the surface of surgical implants, is extensively used in bone tissue engineering applications. β-Tricalcium phosphate/Chitosan (β-TCP/Ch) coatings were deposited on 316L stainless steel (316L SS) substrates by a cathodic electro-deposition technique at different coating compositions. The crystal lattice arrangements were analyzed by X-Ray diffraction (XRD), and the results indicated that the crystallographic structure of β-TCP was affected by the inclusion of the chitosan content. The changes in the surface morphology as a function of increasing chitosan in the coatings via scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that root-mean square values of the β-TCP/Ch coatings decreased by further increasing chitosan percentage. The elastic–plastic characteristics of the coatings were determined by conducting nanoindentation test, indicating that increase of chitosan percentage is directly related to increase of hardness and elastic modulus of the β-TCP/Ch coatings. Tribological characterization was performed by scratch test and pin-on-disk test to analyze the changes in the surface wear of β-TCP/Ch coatings. Finally, the results indicated an improvement in the mechanical and tribological properties of the β-TCP/Ch coatings as a function of increasing of the chitosan percentage. This new class of coatings, comprising the bioactive components, is expected not only to enhance the bioactivity and biocompatibility, but also to protect the surface of metallic implants against wear and corrosion. - Highlights: • Superficial phenomenon that occurs in tribological surface of β-tricalcium phosphate-chitosan coatings. • Improvement on surface mechanical properties of ceramic-polymeric and response to surface tribological damage. • β-tricalcium phosphate-chitosan coatings that offer highest performance in the biomedical devices

Determination of physical properties for β-TCP + chitosan biomaterial obtained on metallic 316L substrates

Energy Technology Data Exchange (ETDEWEB)

Mina, A. [Tribology, Powder Metallurgy and Processing of Solid Recycled Research Group, Universidad del Valle, Cali (Colombia); Tecno-Academia ASTIN SENA Reginal Valle (Colombia); Castaño, A. [Tribology, Powder Metallurgy and Processing of Solid Recycled Research Group, Universidad del Valle, Cali (Colombia); Caicedo, J.C., E-mail: julio.cesar.caicedo@correo.univalle.edu.co [Tribology, Powder Metallurgy and Processing of Solid Recycled Research Group, Universidad del Valle, Cali (Colombia); Caicedo, H.H. [Biologics Research, Biotechnology Center of Excellence, Janssen R& D, LLC, Pharmaceutical Companies of Johnson & Johnson, Spring House, PA 19477 (United States); National Biotechnology & Pharmaceutical Association, Chicago, IL 60606 (United States); Aguilar, Y. [Tribology, Powder Metallurgy and Processing of Solid Recycled Research Group, Universidad del Valle, Cali (Colombia)

2015-06-15

Material surface modification, particularly the deposition of special coatings on the surface of surgical implants, is extensively used in bone tissue engineering applications. β-Tricalcium phosphate/Chitosan (β-TCP/Ch) coatings were deposited on 316L stainless steel (316L SS) substrates by a cathodic electro-deposition technique at different coating compositions. The crystal lattice arrangements were analyzed by X-Ray diffraction (XRD), and the results indicated that the crystallographic structure of β-TCP was affected by the inclusion of the chitosan content. The changes in the surface morphology as a function of increasing chitosan in the coatings via scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that root-mean square values of the β-TCP/Ch coatings decreased by further increasing chitosan percentage. The elastic–plastic characteristics of the coatings were determined by conducting nanoindentation test, indicating that increase of chitosan percentage is directly related to increase of hardness and elastic modulus of the β-TCP/Ch coatings. Tribological characterization was performed by scratch test and pin-on-disk test to analyze the changes in the surface wear of β-TCP/Ch coatings. Finally, the results indicated an improvement in the mechanical and tribological properties of the β-TCP/Ch coatings as a function of increasing of the chitosan percentage. This new class of coatings, comprising the bioactive components, is expected not only to enhance the bioactivity and biocompatibility, but also to protect the surface of metallic implants against wear and corrosion. - Highlights: • Superficial phenomenon that occurs in tribological surface of β-tricalcium phosphate-chitosan coatings. • Improvement on surface mechanical properties of ceramic-polymeric and response to surface tribological damage. • β-tricalcium phosphate-chitosan coatings that offer highest performance in the biomedical devices.

A GA-based PID active queue management control design for TCP/IP networks

Energy Technology Data Exchange (ETDEWEB)

Kuo, H-H; Chen, C-K; Liao, T-L [Department of Engineering Science, National Cheng Kung University, Tainan 701, Taiwan (China); Yan, J-J [Department of Computer and Communication, Shu-Te University, Kaohsiung 824, Taiwan (China)], E-mail: tlliao@mail.ncku.edu.tw

2008-02-15

In this paper, a genetic algorithm-based (GA-based) proportional-integral-derivative (PID) controller as an active queue manager for Internet routers is proposed to reduce packet loss and improve network utilization in TCP/IP networks. Based on the window-based nonlinear dynamics, the TCP network was modeled as a time-delayed system with a saturated input due to the limitations of packet-dropping probability and the effects of propagation delays in TCP networks. An improved genetic algorithm is employed to derive optimal or near optimal PID control gains such that a performance index of integrated-absolute error (IAE) in terms of the error between the router queue length and the desired queue length is minimized. The performance of the proposed control scheme was evaluated in various network scenarios via a series of numerical simulations. The simulation results confirm that the proposed scheme outperforms other AQM schemes.

A GA-based PID active queue management control design for TCP/IP networks

International Nuclear Information System (INIS)

Kuo, H-H; Chen, C-K; Liao, T-L; Yan, J-J

2008-01-01

In this paper, a genetic algorithm-based (GA-based) proportional-integral-derivative (PID) controller as an active queue manager for Internet routers is proposed to reduce packet loss and improve network utilization in TCP/IP networks. Based on the window-based nonlinear dynamics, the TCP network was modeled as a time-delayed system with a saturated input due to the limitations of packet-dropping probability and the effects of propagation delays in TCP networks. An improved genetic algorithm is employed to derive optimal or near optimal PID control gains such that a performance index of integrated-absolute error (IAE) in terms of the error between the router queue length and the desired queue length is minimized. The performance of the proposed control scheme was evaluated in various network scenarios via a series of numerical simulations. The simulation results confirm that the proposed scheme outperforms other AQM schemes

MAC-layer protocol for TCP fairness in Wireless Mesh Networks

KAUST Repository

Nawab, Faisal

2012-08-01

In this paper we study the interactions of TCP and IEEE 802.11 MAC in Wireless Mesh Networks (WMNs). We use a Markov chain to capture the behavior of TCP sessions, particularly the impact on network throughput performance due to the effect of queue utilization and packet relaying. A closed form solution is derived to numerically determine the throughput. Based on the developed model, we propose a distributed MAC protocol to alleviate the unfairness problem in WMNs. Our protocol uses the age of packet as a priority metric for packet scheduling. Simulation is conducted to validate our model and to illustrate the fairness characteristics of our proposed MAC protocol. We conclude that we can achieve fairness with only little impact on network capacity.

DeltaShaper: Enabling Unobservable Censorship-resistant TCP Tunneling over Videoconferencing Streams

Directory of Open Access Journals (Sweden)

Barradas Diogo

2017-10-01

Full Text Available This paper studies the possibility of using the encrypted video channel of widely used videoconferencing applications, such as Skype, as a carrier for unobservable covert TCP/IP communications. We propose and evaluate different alternatives to encode information in the video stream in order to increase available throughput while preserving the packet-level characteristics of the video stream. We have built a censorship-resistant system, named DeltaShaper, which offers a data-link interface and supports TCP/IP applications that tolerate low throughput / high latency links. Our results show that it is possible to run standard protocols such as FTP, SMTP, or HTTP over Skype video streams.

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

Science.gov (United States)

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.

Genomewide analysis of TCP transcription factor gene family in ...

Indian Academy of Sciences (India)

2014-12-09

Dec 9, 2014 ... study of a genomewide analysis of apple TCP gene family. These results provide .... synthesize the first-strand cDNA using the PrimeScript First. Strand cDNA ..... only detected in the stem, leaf and fruit (figure 8). When.

Performance of TCP over UMTS common and dedicated channels

NARCIS (Netherlands)

Lo, Anthony; Heijenk, Geert; Bruma, Cezar; Gameiro, A.

2003-01-01

Universal Mobile Telecommunications System (UMTS) is a third-generation cellular network that enables high-speed wireless Internet access. This paper investigates the performance of Transmission Control Protocol (TCP) over UMTS utilizing a common and four dedicated transport channels with bit rates

Effects of BMP-2 and dexamethasone on osteogenic differentiation of rat dental follicle progenitor cells seeded on three-dimensional β-TCP

International Nuclear Information System (INIS)

Xu Lulu; Jin Zuolin; Duan Yinzhong; Liu Hongchen; Wang Dongsheng; E Lingling; Xu Lin

2009-01-01

The aim of this study was to investigate the effects of BMP-2 and dexamethasone (Dex) on osteogenic differentiation of rat dental follicle progenitor cells (RDFCs) seeded on three-dimensional β-TCP. The alkaline phosphatase (ALP), the calcium and phosphonium, the osteocalcin in media of the third passage RDFCs on biomaterial β-TCP after 1-3, 3-7, 7-14 days of culture were examined respectively. The growth of cells on the scaffolds was observed by scanning electron microscope (SEM) after 3, 7 days of culture and by implanting in the backs of severe combined immunodeficient (SCID) mice for bone regeneration. The third passage RDFCs could be seen adhered, extended and proliferated on the β-TCP by scanning electron microscopy. The ALP activity, the calcium and phosphoniums and the osteocalcin content of dexamethasone (10 -8 M) or/and BMP-2 (100 ng ml -1 ) were significantly higher than their existence in the control group. They were the significantly highest among four groups after joint application of BMP-2 and dexamethasone. After 8 weeks of implantation, the percentage of the new bones formed area in the RDFCs+β-TCP+BMP-2+Dex group was significantly higher than that in the RDFCs+β-TCP+BMP-2 group. In contrast, β-TCP, RDFCs+β-TCP+Dex and control constructs lacked new bone formation by histological staining and histomorphometric analysis. The BMP-2+Dex could significantly promote osteogenic differentiation of RDFCs on β-TCP. β-TCP supported fast cellular adhesion, proliferation and differentiation of RDFCs. The feasibility of its application in periodontal tissue engineering was also proved.

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

Directory of Open Access Journals (Sweden)

Indu Bajpai

2016-01-01

Full Text Available 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.

A Novel Congestion Detection Scheme in TCP Over OBS Networks

KAUST Repository

Shihada, Basem; Ho, Pin-Han; Zhang, Qiong

2009-01-01

This paper introduces a novel congestion detection scheme for high-bandwidth TCP flows over optical burst switching (OBS) networks, called statistical additive increase multiplicative decrease (SAIMD). SAIMD maintains and analyzes a number

Release Kinetics and Antibacterial Efficacy of Microporous β-TCP Coatings

Directory of Open Access Journals (Sweden)

Michael Seidenstuecker

2013-01-01

Full Text Available Purpose. The aim of this study was to impregnate microporous β-TCP scaffolds with different antibiotic solutions and to determine their release behavior. Materials and Methods. We impregnated a β-TCP scaffold with antibiotics by using three methods: drop, dip, and stream coating with 120 mg/mL of antibiotic solution. After drying for 72 h at 37°C, 2 mL of distilled water was added to the antibiotic-coated plugs and incubated at 37°C. After defined time points (1, 2, 3, 6, 9, and 14 days, the liquid was completely replaced. The extracted liquid was analyzed by capillary zone electrophoresis and the Kirby Bauer disc diffusion test. For statistical analysis, we calculated a mean and standard deviation and carried out an analysis of variance using ANOVA. Results. The VAN and CLI release from the β-TCP scaffolds was rapid, occurring within 24 h with 89 ± 0.8% VAN and 90.4 ± 1.5% CLI regardless of the type of insulation. After six days, the VAN and CLI were completely released. All samples taken at later time points had a VAN or CLI concentration below the detection limit of 4 µg/mL. The released amounts of VAN and CLI within the first three days revealed antimicrobial activity.

The therapeutic effect on bone mineral formation from biomimetic zinc containing tricalcium phosphate (ZnTCP in zinc-deficient osteoporotic mice.

Directory of Open Access Journals (Sweden)

Joshua Chou

Full Text Available The aim of this study was to evaluate the therapeutic efficacy of biomimetic zinc-containing tricalcium phosphate (ZnTCP produced by hydrothermally converting calcium carbonate exoskeletons from foraminifera, in the treatment of osteoporotic mice. X-Ray powder diffraction showed crystallographic structures matching JCPDS profile for tricalcium phosphate. Mass spectroscopy used to calculate total composition amount showed similar amount of calcium (5×10(4 µg/g and phosphate (4×10(4 ppm after conversion and the presence of zinc (5.18×10(3 µg/g. In vitro zinc release showed no release in PBS buffer and <1% zinc release in 7 days. In vivo evaluation was done in ovariectomized mice by implanting the ZnTCP samples in the soft tissues near the right femur bone for four weeks. Thirty ddY mice (5 weeks old, average weight of 21 g were divided into six experimental groups (normal, sham, OVX, β-TCP, ZnTCP and direct injection of zinc. CT images were taken every two weeks where the bone mineral density (BMD and bone mineral content (BMC were calculated by software based on CT images. The ZnTCP group exhibits cortical and cancellous bone growth of 45% and 20% respectively. While sham, OVX and β-TCP suffered from bone loss. A correlation was made between the significant body weight increase in ZnTCP with the significant increase in plasma zinc level compared with OVX. The presented results indicate that biomimetic ZnTCP were effective in preventing and treating bone loss in osteoporotic mice model.

Long T2 suppression in native lung 3-D imaging using k-space reordered inversion recovery dual-echo ultrashort echo time MRI.

Science.gov (United States)

Gai, Neville D; Malayeri, Ashkan A; Bluemke, David A

2017-08-01

Long T2 species can interfere with visualization of short T2 tissue imaging. For example, visualization of lung parenchyma can be hindered by breathing artifacts primarily from fat in the chest wall. The purpose of this work was to design and evaluate a scheme for long T2 species suppression in lung parenchyma imaging using 3-D inversion recovery double-echo ultrashort echo time imaging with a k-space reordering scheme for artifact suppression. A hyperbolic secant (HS) pulse was evaluated for different tissues (T1/T2). Bloch simulations were performed with the inversion pulse followed by segmented UTE acquisition. Point spread function (PSF) was simulated for a standard interleaved acquisition order and a modulo 2 forward-reverse acquisition order. Phantom and in vivo images (eight volunteers) were acquired with both acquisition orders. Contrast to noise ratio (CNR) was evaluated in in vivo images prior to and after introduction of the long T2 suppression scheme. The PSF as well as phantom and in vivo images demonstrated reduction in artifacts arising from k-space modulation after using the reordering scheme. CNR measured between lung and fat and lung and muscle increased from -114 and -148.5 to +12.5 and 2.8 after use of the IR-DUTE sequence. Paired t test between the CNRs obtained from UTE and IR-DUTE showed significant positive change (p lung-fat CNR and p = 0.03 for lung-muscle CNR). Full 3-D lung parenchyma imaging with improved positive contrast between lung and other long T2 tissue types can be achieved robustly in a clinically feasible time using IR-DUTE with image subtraction when segmented radial acquisition with k-space reordering is employed.

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

Science.gov (United States)

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.

Optimal production lot size and reorder point of a two-stage supply chain while random demand is sensitive with sales teams' initiatives

Science.gov (United States)

Sankar Sana, Shib

2016-01-01

The paper develops a production-inventory model of a two-stage supply chain consisting of one manufacturer and one retailer to study production lot size/order quantity, reorder point sales teams' initiatives where demand of the end customers is dependent on random variable and sales teams' initiatives simultaneously. The manufacturer produces the order quantity of the retailer at one lot in which the procurement cost per unit quantity follows a realistic convex function of production lot size. In the chain, the cost of sales team's initiatives/promotion efforts and wholesale price of the manufacturer are negotiated at the points such that their optimum profits reached nearer to their target profits. This study suggests to the management of firms to determine the optimal order quantity/production quantity, reorder point and sales teams' initiatives/promotional effort in order to achieve their maximum profits. An analytical method is applied to determine the optimal values of the decision variables. Finally, numerical examples with its graphical presentation and sensitivity analysis of the key parameters are presented to illustrate more insights of the model.

TRAP: A Three-Way Handshake Server for TCP Connection Establishment

Directory of Open Access Journals (Sweden)

Fu-Hau Hsu

2016-11-01

Full Text Available Distributed denial of service attacks have become more and more frequent nowadays. In 2013, a massive distributed denial of service (DDoS attack was launched against Spamhaus causing the service to shut down. In this paper, we present a three-way handshaking server for Transmission Control Protocol (TCP connection redirection utilizing TCP header options. When a legitimate client attempted to connect to a server undergoing an SYN-flood DDoS attack, it will try to initiate a three-way handshake. After it has successfully established a connection, the server will reply with a reset (RST packet, in which a new server address and a secret is embedded. The client can, thus, connect to the new server that only accepts SYN packets with the corrected secret using the supplied secret.

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

Science.gov (United States)

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.

Effects of BMP-2 and dexamethasone on osteogenic differentiation of rat dental follicle progenitor cells seeded on three-dimensional beta-TCP

Energy Technology Data Exchange (ETDEWEB)

Xu Lulu; Jin Zuolin; Duan Yinzhong [Department of Orthodontics, Stomatological College, Fourth Military Medical University, Xi' an 710032 (China); Liu Hongchen; Wang Dongsheng; E Lingling [Department of Stomatology, China PLA General Hospital, Beijing 100853 (China); Xu Lin, E-mail: jinzuolin88@yahoo.com.c, E-mail: duanyinzhong@yahoo.com.c [Department of Stomatology, the First Hospital of PLA, Lanzhou 730000 (China)

2009-12-15

The aim of this study was to investigate the effects of BMP-2 and dexamethasone (Dex) on osteogenic differentiation of rat dental follicle progenitor cells (RDFCs) seeded on three-dimensional beta-TCP. The alkaline phosphatase (ALP), the calcium and phosphonium, the osteocalcin in media of the third passage RDFCs on biomaterial beta-TCP after 1-3, 3-7, 7-14 days of culture were examined respectively. The growth of cells on the scaffolds was observed by scanning electron microscope (SEM) after 3, 7 days of culture and by implanting in the backs of severe combined immunodeficient (SCID) mice for bone regeneration. The third passage RDFCs could be seen adhered, extended and proliferated on the beta-TCP by scanning electron microscopy. The ALP activity, the calcium and phosphoniums and the osteocalcin content of dexamethasone (10{sup -8} M) or/and BMP-2 (100 ng ml{sup -1}) were significantly higher than their existence in the control group. They were the significantly highest among four groups after joint application of BMP-2 and dexamethasone. After 8 weeks of implantation, the percentage of the new bones formed area in the RDFCs+beta-TCP+BMP-2+Dex group was significantly higher than that in the RDFCs+beta-TCP+BMP-2 group. In contrast, beta-TCP, RDFCs+beta-TCP+Dex and control constructs lacked new bone formation by histological staining and histomorphometric analysis. The BMP-2+Dex could significantly promote osteogenic differentiation of RDFCs on beta-TCP. beta-TCP supported fast cellular adhesion, proliferation and differentiation of RDFCs. The feasibility of its application in periodontal tissue engineering was also proved.

Adaptive optimization for active queue management supporting TCP flows

NARCIS (Netherlands)

Baldi, S.; Kosmatopoulos, Elias B.; Pitsillides, Andreas; Lestas, Marios; Ioannou, Petros A.; Wan, Y.; Chiu, George; Johnson, Katie; Abramovitch, Danny

2016-01-01

An adaptive decentralized strategy for active queue management of TCP flows over communication networks is presented. The proposed strategy solves locally, at each link, an optimal control problem, minimizing a cost composed of residual capacity and buffer queue size. The solution of the optimal

Synthesis and degradation properties of β-TCP/BG porous ...

Indian Academy of Sciences (India)

-TCP/BG porous composite materials were successfully fabricated by foaming technology. X-ray diffraction was used to determine the crystal structure of powders. The pore size and distribution of the resulting materials were characterized using scanning electron microscopy. The porosity and degradation performance of ...

Bone Regeneration of Rat Tibial Defect by Zinc-Tricalcium Phosphate (Zn-TCP Synthesized from Porous Foraminifera Carbonate Macrospheres

Directory of Open Access Journals (Sweden)

Joshua Chou

2013-12-01

Full Text Available Foraminifera carbonate exoskeleton was hydrothermally converted to biocompatible and biodegradable zinc-tricalcium phosphate (Zn-TCP as an alternative biomimetic material for bone fracture repair. Zn-TCP samples implanted in a rat tibial defect model for eight weeks were compared with unfilled defect and beta-tricalcium phosphate showing accelerated bone regeneration compared with the control groups, with statistically significant bone mineral density and bone mineral content growth. CT images of the defect showed restoration of cancellous bone in Zn-TCP and only minimal growth in control group. Histological slices reveal bone in-growth within the pores and porous chamber of the material detailing good bone-material integration with the presence of blood vessels. These results exhibit the future potential of biomimetic Zn-TCP as bone grafts for bone fracture repair.

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

Directory of Open Access Journals (Sweden)

Eun-Bin Bae

2018-01-01

Full Text Available 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 (mm3 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.

Satellite communication on pipeline supervision using TCP-IP Protocol; Comunicacao via satelite na supervisao de dutos usando o protocolo TCP-IP

Energy Technology Data Exchange (ETDEWEB)

Silva, Agliberto Pessoa da [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Brunette, Sergio Henrique de Moraes

2003-07-01

Bit transparent type or X-25 protocols have been used in VSAT satellite communication by PETROBRAS pipeline Supervisory Control and Data Acquisition System (SCADA) as access protocol. Both solutions have inconveniences. By the first one, difficulties exist for analysis and diagnosis of connection flaws, and therefore, for a ready identification by the system management stations of abnormality location. On the other hand, the usage of the X-25 brings an additional over-head in the communication since this is not an available option in most of the equipment that compose the SCADA. The access to VSAT through Ethernet, in the opposite, makes available all networks management tools of the TCP/IP platform and it allows a direct connection to the field devices, since the main models of the several makers of Programmable Controllers and Remote Terminal Units have Ethernet port. An additional earnings is the possibility of standardization that this solution allows. This paper describes a series of communication tests between two Programmable Controllers communicating through the satellite, using a protocol over Ethernet/TCP/IP. (author)

Versatile Markovian models for networks with asymmetric TCP sources

NARCIS (Netherlands)

van Foreest, N.D.; Haverkort, Boudewijn R.H.M.; Mandjes, M.R.H.; Scheinhardt, Willem R.W.

2004-01-01

In this paper we use Stochastic Petri Nets (SPNs) to study the interaction of multiple TCP sources that share one or two buffers, thereby considerably extending earlier work. We first consider two sources sharing a buffer and investigate the consequences of two popular assumptions for the loss

Preparation and in vitro evaluation of nanostructured TiO2/TCP composite coating by plasma electrolytic oxidation

International Nuclear Information System (INIS)

Hu, Hongjie; Liu, Xuanyong; Ding, Chuanxian

2010-01-01

Porous and nanostructured TiO 2 /tricalcium phosphate (TCP) composite coating on titanium substrate was prepared by plasma electrolytic oxidation (PEO). The microstructure and phase composition of the coating were characterized using scanning electron microscopy and X-ray diffraction. Its bioactivity was evaluated by simulated body fluid (SBF) immersion tests. MG63 cells were cultured on the surface of the coating to investigate its cytocompatibility. Potentiodynamic polarization tests were applied to measure its corrosion resistance. The results revealed that rough and hydrophilic TiO 2 /TCP composite coating with pores of several micrometers and grains of 50-200 nm was prepared by one-step PEO treatment. The TiO 2 /TCP composite coating showed good apatite-forming ability in SBF, and the TCP phase in the coating played an important role in inducing apatite formation. MG63 cells could adhere and proliferate on the surface of the coating, indicating its good cytocompatibility. The composite coating also exhibited good corrosion resistance in 0.9% NaCl solution.

Optimizing TCP Performance in Multi-AP Residential Broadband Connections via Minislot Access

Directory of Open Access Journals (Sweden)

Domenico Giustiniano

2013-01-01

Full Text Available The high bandwidth demand of Internet applications has recently driven the need of increasing the residential download speed. A practical solution to the problem is to aggregate the bandwidth of 802.11 access points (APs backhauls in range. Since 802.11 devices are usually single radio, the communication to APs on different radio channels requires a time-division multiple access (TDMA policy at the client station. With an in-depth experimental analysis and a customized 802.11 driver, in this paper, we show that the usage of multi-AP TDMA policy may cause degradation of the TCP throughput and an underutilization of the AP backhauls. We then introduce a simple analytical model that accurately predicts the TCP round-trip time (RTT with a multi-AP TDMA policy and propose a resource allocation algorithm to reduce the observed TCP RTT with a very low computational cost. Our proposed scheme runs locally at the client station and improves the aggregate throughput up to 1.5 times compared to state-of-the-art allocations. We finally show that the throughput achieved by our algorithm is very close to the theoretical upper bound in key simulation scenarios.

Optimising TCP for cloud-based mobile networks

DEFF Research Database (Denmark)

Artuso, Matteo; Christiansen, Henrik Lehrmann

2016-01-01

Cloud-based mobile networks are foreseen to be a technological enabler for the next generation of mobile networks. Their design requires substantial research as they pose unique challenges, especially from the point of view of additional delays in the fronthaul network. Commonly used network...... implementations of 3 popular operating systems are investigated in our network model. The results on the most influential parameters are used to design an optimized TCP for cloud-based mobile networks....

TULIP: A Link-Level Protocol for Improving TCP over Wireless Links

National Research Council Canada - National Science Library

Parsa, Christina; Garcia-Luna-Aceves, J. J

1999-01-01

We present the transport unaware link improvement protocol (TULIP), which dramatically improves the performance of TCP over lossy wireless links, without competing with or modifying the transport- or network-layer protocols...

Parallel evolution of TCP and B-class genes in Commelinaceae flower bilateral symmetry

Directory of Open Access Journals (Sweden)

Preston Jill C

2012-03-01

Full Text Available Abstract Background Flower bilateral symmetry (zygomorphy has evolved multiple times independently across angiosperms and is correlated with increased pollinator specialization and speciation rates. Functional and expression analyses in distantly related core eudicots and monocots implicate independent recruitment of class II TCP genes in the evolution of flower bilateral symmetry. Furthermore, available evidence suggests that monocot flower bilateral symmetry might also have evolved through changes in B-class homeotic MADS-box gene function. Methods In order to test the non-exclusive hypotheses that changes in TCP and B-class gene developmental function underlie flower symmetry evolution in the monocot family Commelinaceae, we compared expression patterns of teosinte branched1 (TB1-like, DEFICIENS (DEF-like, and GLOBOSA (GLO-like genes in morphologically distinct bilaterally symmetrical flowers of Commelina communis and Commelina dianthifolia, and radially symmetrical flowers of Tradescantia pallida. Results Expression data demonstrate that TB1-like genes are asymmetrically expressed in tepals of bilaterally symmetrical Commelina, but not radially symmetrical Tradescantia, flowers. Furthermore, DEF-like genes are expressed in showy inner tepals, staminodes and stamens of all three species, but not in the distinct outer tepal-like ventral inner tepals of C. communis. Conclusions Together with other studies, these data suggest parallel recruitment of TB1-like genes in the independent evolution of flower bilateral symmetry at early stages of Commelina flower development, and the later stage homeotic transformation of C. communis inner tepals into outer tepals through the loss of DEF-like gene expression.

MULTIMEDIA DATA TRANSMISSION THROUGH TCP/IP USING HASH BASED FEC WITH AUTO-XOR SCHEME

OpenAIRE

R. Shalin; D. Kesavaraja

2012-01-01

The most preferred mode for communication of multimedia data is through the TCP/IP protocol. But on the other hand the TCP/IP protocol produces huge packet loss unavoidable due to network traffic and congestion. In order to provide a efficient communication it is necessary to recover the loss of packets. The proposed scheme implements Hash based FEC with auto XOR scheme for this purpose. The scheme is implemented through Forward error correction, MD5 and XOR for providing efficient transmissi...

YottaYotta announces new world record set for TCP disk-to-disk bulk transfer

CERN Document Server

2002-01-01

The Yottabyte NetStorage(TM) Company, today announced a new world record for TCP disk-to-disk data transfer using the company's NetStorager(R) System. The record-breaking demonstration transferred 5 terabytes of data between Chicago, Il. to Vancouver, BC and Ottawa, ON, at a sustained average throughput of 11.1 gigabits per second. Peak throughput exceeded 11.6 gigabits per second, more than 15-times faster than previous records for TCP transfer from disk-to-disk (1 page).

ejIP: A TCP/IP Stack for Embedded Java

DEFF Research Database (Denmark)

Schoeberl, Martin

2011-01-01

present the design and implementation of a network stack written entirely in Java. This implementation serves as an example how to implement system functions in a safe language and gives evidence that Java can be used for operating system related functionality. The described TCP/IP stack ejIP has already...

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

Science.gov (United States)

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…

Proliferation and osteogenic differentiation of human periodontal ligament cells on akermanite and β-TCP bioceramics

Directory of Open Access Journals (Sweden)

L Xia

2011-07-01

Full Text Available The purpose of this study was to investigate the effects of akermanite as compared to β-TCP on attachment, proliferation, and osteogenic differentiation of human periodontal ligament cells (hPDLCs. Scanning electron microscopy (SEM and actin filament labeling were used to reveal attachment and growth of hPDLCs seeded on β-TCP and akermanite ceramic. Cell proliferation was tested by lactic acid production and MTT analysis, while osteogenic differentiation was assayed by alkaline phosphatase (ALP expression and real-time polymerase chain reaction (PCR analysis on markers of osteopontin (OPN, dentin matrix acidic phosphoprotein-1 (DMP-1, and osteocalcin (OCN, and further detected by enzyme-linked immunosorbent analysis (ELISA analysis for OCN expression. Besides, the ions released from akermanite and their effect on hPDLCs was also measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES, MTT analysis, ALP expression and real-time PCR analysis. hPDLCs attached well on both ceramics, but showed better spreading on akermanite. hPDLCs proliferated more rapidly on akermanite than β-TCP. Importantly, osteogenic differentiation of hPDLCs was enhanced on akermanite compared to β-TCP. Besides, Ca, Mg and Si ions were released from akermanite, while only Ca ions were released from β-TCP. Moreover, more pronounced proliferation and higher osteogenic gene expression for hPDLCs cultured with akermanite extract were detected as compared to cells cultured on akermanite. Therefore, akermanite ceramic showed an enhanced effect on proliferation and osteogenic differentiation of hPDLCs, which might be attributed to the release of ions containing Ca, Mg and Si from the material. It is suggested that akermanite ceramics may serve as a potential material for periodontal bone regeneration.

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

Science.gov (United States)

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.

Fabrication and evaluation of 3D β-TCP scaffold by novel direct-write assembly method

International Nuclear Information System (INIS)

Sa, Min Woo; Kim, Jong Young

2015-01-01

Various scaffold fabrication methods have been explored to enhance the cell interaction effects and mechanical properties of scaffolds in bone regeneration. Rapid prototyping (RP) for tissue engineering is a useful technology that may provide a potential scaffolding structure to regenerate, restore, and repair a damaged bone tissue or organ, that is, RP is a promising tissue engineering technique through a 3D scaffold fabrication by using a computer-aided design/computer-aided manufacturing system. In this study, 3D β-tricalcium phosphate (β-TCP) scaffolds were fabricated by a novel direct-write assembly method. The mechanical property of β-TCP scaffolds was analyzed by stress-strain curves by using a compression testing machine. Furthermore, an in vitro CCK-8 assay of osteosarcoma MG-63 cells showed the significant cell attachment and proliferation in the β-TCP scaffold.

Fabrication and evaluation of 3D β-TCP scaffold by novel direct-write assembly method

Energy Technology Data Exchange (ETDEWEB)

Sa, Min Woo; Kim, Jong Young [Andong National University, Andong (Korea, Republic of)

2015-11-15

Various scaffold fabrication methods have been explored to enhance the cell interaction effects and mechanical properties of scaffolds in bone regeneration. Rapid prototyping (RP) for tissue engineering is a useful technology that may provide a potential scaffolding structure to regenerate, restore, and repair a damaged bone tissue or organ, that is, RP is a promising tissue engineering technique through a 3D scaffold fabrication by using a computer-aided design/computer-aided manufacturing system. In this study, 3D β-tricalcium phosphate (β-TCP) scaffolds were fabricated by a novel direct-write assembly method. The mechanical property of β-TCP scaffolds was analyzed by stress-strain curves by using a compression testing machine. Furthermore, an in vitro CCK-8 assay of osteosarcoma MG-63 cells showed the significant cell attachment and proliferation in the β-TCP scaffold.

A novel implementation of TCP Vegas for optical burst switched networks

KAUST Repository

Shihada, Basem; Zhang, Qiong; Ho, Pin-Han; Jue, Jason P.

2010-01-01

TCP performance over bufferless Optical Burst Switched (OBS) networks could be significantly degraded due to the misinterpretation of network congestion status (referred to as false congestion detection). It has been reported that burst

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

Procesamiento cerámico de β-TCP para la fabricación de piezas implantables

Directory of Open Access Journals (Sweden)

Franco, J.

2006-08-01

Full Text Available This work describes a method for obtaining large-scale productions of β-TCP by mass-precipitation from calcium and phosphate solutions. The setting of the synthesis conditions was made by studying operational parameters like the concentrations of the reagents, the speed of the mixing of the reagents, pH of precipitation and ageing of the precipitate. This synthesis procedure allows obtaining high purity β-TCP under ASTM F1088-87. Starting from synthesized β-TCP were made rods for implantation by die pressing, slip casting, gel casting and low pressure injection moulding. These rods were well characterized and implanted in Beagle dogs. Thin film histological results for 2, 7, and 14 months of implantation period, shown a good biocompatibility for the material and its resorbable behaviour.

El trabajo describe la puesta a punto de un método de obtención de grandes cantidades de fosfato tricálcico (β-TCP, por precipitación a partir de disoluciones de sales de calcio y de fosfatos. Para ello se estudia la influencia de los parámetros de operación tales como concentración de reactivos, velocidad de adición, pH de precipitación y tiempo de envejecimiento del precipitado. El procedimiento, que es escalable a nivel industrial, permite obtener β-TCP de elevada pureza, que cumple ASTM F1088-87. Con el material obtenido se procesan barras implantables por prensado, colado, gel-casting e inyección, que se caracterizan detalladamente, y posteriormente se implantan en la tibia de perros Beagle. El estudio histológico en lámina delgada de los implantes, tras períodos de implantación de 2, 7 y 14 meses, permite evaluar la excelente biocompatibilidad del material y su carácter reabsorbible.

Chest tcpO2 changes during constant-load treadmill walking tests in patients with claudication

International Nuclear Information System (INIS)

Ouedraogo, N; Leftheriotis, G; Abraham, P; Feuilloy, M; Mahe, G; Saumet, J-L

2011-01-01

Changes in chest transcutaneous-pO 2 at rest (ΔtcpO 2 ) mimic absolute changes in arterial-pO 2 during moderate exercise, although the absolute starting values may dramatically differ. We retrospectively studied 485 patients (group 1), prospectively studied 292 new patients (group 2) and estimated the intra-test and the test–retest reproducibility of ΔtcpO 2 during constant-load treadmill tests: 3.2 km h −1 , 10% grade, using the cross correlation technique. Patients were classified into groups according to their best fit to nine pre-defined mathematic models. Respectively, 71% and 76% of patients of groups 1 and 2 fitted with a model showing a ΔtcpO 2 increase during and a decrease following exercise. Another 18% and 12% of the patients of groups 1 and 2 respectively fitted with a model that showed an abrupt decrease at exercise onset, a slow increase during walking and an overshoot in the recovery period, referred here as a walking-induced transcutaneous hack (WITH) profile. The mean r max value for the cross-correlation analysis was 0.919 ± 0.091 and 0.800 ± 0.129 for intra-test and test–retest reproducibility. Most profiles show the expected ΔtcpO 2 exercise-induced increase. Future studies are needed to confirm and explain the WITH profiles that we found, and screen for potential-associated diseases

"De-Randomizing" Congestion Losses to Improve TCP Performance over Wired-Wireless Networks

National Research Council Canada - National Science Library

Biaz, Saad; Vaidya, Nitin H

2004-01-01

.... With Internet becoming more heterogeneous with more and more wireless error-prone links, a TCP connection may unduly throttle its sending rate and experience poor performance over paths experiencing...

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

Science.gov (United States)

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.

Rapid restoration of methanogenesis in an acidified UASB reactor treating 2,4,6-trichlorophenol (TCP).

Science.gov (United States)

Díaz-Báez, María Consuelo; Valderrama-Rincon, Juan Daniel

2017-02-15

Anaerobic bioreactors are often used for removal of xenobiotic and highly toxic pollutants from wastewater. Most of the time, the pollutant is so toxic that the stability of the reactor becomes compromised. It is well known that methanogens are one of the most sensitive organisms in the anaerobic consortia and hence the stability of the reactors is highly dependant on methanogenesis. Unfortunately few studies have focused on recovering the methanogenic activity once it has been inhibited by highly toxic pollutants. Here we establish a quick recovery strategy for neutralization of an acidified UASB reactor after failure by intoxication with an excess of TCP in the influent. Once the reactor returned to pH values compatible with methanogenesis, biogas production was re-started after one day and the system was re-acclimated to TCP. Successful removal of TCP from synthetic wastewater was shown for concentrations up to 70mg/L after restoration. Copyright © 2016 Elsevier B.V. All rights reserved.

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

Science.gov (United States)

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.

FAST TCP over optical burst switched networks: Modeling and stability analysis

KAUST Repository

Shihada, Basem; El-Ferik, Sami; Ho, Pin-Han

2013-01-01

congestion-control mechanism in bufferless Optical Burst Switched Networks (OBS). The paper first shows that random burst contentions are essential to stabilize the network, but cause throughput degradation in FAST TCP flows when a burst with all the packets

Characterization of General TCP Traffic under a Large Number of Flows Regime

National Research Council Canada - National Science Library

Tinnakornsrisuphap, Peerapol; La, Richard J; Makowski, Armand M

2002-01-01

.... Accurate traffic modeling of a large number of short-lived TCP flows is extremely difficult due to the interaction between session, transport, and network layers, and the explosion of the size...

Construction of a nuclear data server using TCP/IP

Energy Technology Data Exchange (ETDEWEB)

Kawano, Toshihiko; Sakai, Osamu [Kyushu Univ., Fukuoka (Japan)

1997-03-01

We construct a nuclear data server which provides data in the evaluated nuclear data library through the network by means of TCP/IP. The client is not necessarily a user but a computer program. Two examples with a prototype server program are demonstrated, the first is data transfer from the server to a user, and the second is to a computer program. (author)

Electrospun Gelatin/β-TCP Composite Nanofibers Enhance Osteogenic Differentiation of BMSCs and In Vivo Bone Formation by Activating Ca2+-Sensing Receptor Signaling

Directory of Open Access Journals (Sweden)

Xuehui Zhang

2015-01-01

Full Text Available 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 Ca2+-sensing receptor signaling.

MULTIMEDIA DATA TRANSMISSION THROUGH TCP/IP USING HASH BASED FEC WITH AUTO-XOR SCHEME

Directory of Open Access Journals (Sweden)

R. Shalin

2012-09-01

Full Text Available The most preferred mode for communication of multimedia data is through the TCP/IP protocol. But on the other hand the TCP/IP protocol produces huge packet loss unavoidable due to network traffic and congestion. In order to provide a efficient communication it is necessary to recover the loss of packets. The proposed scheme implements Hash based FEC with auto XOR scheme for this purpose. The scheme is implemented through Forward error correction, MD5 and XOR for providing efficient transmission of multimedia data. The proposed scheme provides transmission high accuracy, throughput and low latency and loss.

Microfibrous {beta}-TCP/collagen scaffolds mimic woven bone in structure and composition

Energy Technology Data Exchange (ETDEWEB)

Zhang Shen; Zhang Xin; Cai Qing; Yang Xiaoping [Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Wang Bo; Deng Xuliang, E-mail: yangxp@mail.buct.edu.c [Department of VIP Dental Service, School and Hospital of Stomatology, Peking University, Beijing 100081 (China)

2010-12-15

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 ({beta}-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 {beta}-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 {beta}-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.

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

International Nuclear Information System (INIS)

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

2010-01-01

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.

Analysis of functional redundancies within the Arabidopsis TCP transcription factor family

NARCIS (Netherlands)

Danisman, S.; Dijk, van A.D.J.; Bimbo, A.; Wal, van der F.; Hennig, L.; Folter, de S.; Angenent, G.C.; Immink, R.G.H.

2013-01-01

Analyses of the functions of TEOSINTE-LIKE1, CYCLOIDEA, and ROLIFERATING 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

Microstructure, mechanical property and corrosion behavior of interpenetrating (HA + β-TCP)/MgCa composite fabricated by suction casting

International Nuclear Information System (INIS)

Wang, X.; Dong, L.H.; Li, J.T.; Li, X.L.; Ma, X.L.; Zheng, Y.F.

2013-01-01

The novel interpenetrating (HA + β-TCP)/MgCa composites were fabricated by infiltrating MgCa alloy into porous HA + β-TCP using suction casting technique. The microstructure, mechanical properties and corrosion behaviors of the composites have been evaluated by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), mechanical testing, electrochemical and immersion tests. It was shown that the composites had compact structure and the interfacial bonding between MgCa alloy and HA + β-TCP scaffolds was very well. The ultimate compressive strength of the composites was about 500–1000 fold higher than that of the original porous scaffolds, and it still retained quarter-half of the strength of the bulk MgCa alloy. The electrochemical and immersion tests indicated that the corrosion resistance of the composites was better than that of the MgCa matrix alloy, and the corrosion products of the composite surface were mainly Mg(OH) 2 , HA and Ca 3 (PO 4 ) 2 . Meanwhile, the mechanical and corrosive properties of the (HA + β-TCP)/MgCa composites were adjustable by the choice of HA content. - Highlights: • The composites were fabricated by infiltrating MgCa alloy into porous HA + β-TCP. • The microstructure, mechanical and corrosion properties were investigated. • It showed composites had compact structures and good interfacial bonding. • The mechanical and corrosive properties can be adjustable by the HA content. • The corrosion mechanism of the composite has been explained

A Network Steganography Lab on Detecting TCP/IP Covert Channels

Science.gov (United States)

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…

Truncated power control for improving TCP/IP performance over CDMA wireless links

DEFF Research Database (Denmark)

Cianca, Ernestina; Prasad, Ramjee; De Sanctis, Mauro

2005-01-01

The issue of the performance degradation of transmission control protocol/Internet Protocol (TCP/IP) over wireless links due to the presence of noncongestion-related packet losses has been addressed with a physical layer approach. The effectiveness of automatic repeat request techniques...... in enhancing TCP/IP performance depends on the tradeoff between frame transmission delay and residual errors after retransmissions. The paper shows how a truncated power control can be effectively applied to improve that tradeoff so that a higher transmission reliability is provided without increasing...... the frame transmission delay through the radio link layer and without increasing the energy consumption. An analytical framework has been developed to show the feasibility and effectiveness of the proposed power control. The analytical results, which are carried out assuming a constant multiuser...

Reducing Communication Overhead by Scheduling TCP Transfers on Mobile Devices using Wireless Network Performance Maps

DEFF Research Database (Denmark)

Højgaard-Hansen, Kim; Madsen, Tatiana Kozlova; Schwefel, Hans-Peter

2012-01-01

The performance of wireless communication networks has been shown to have a strong location dependence. Measuring the performance while having accurate location information available makes it possible to generate performance maps. In this paper we propose a framework for the generation and use...... of such performance maps. We demonstrate how the framework can be used to reduce the retransmissions and to better utilise network resources when performing TCP-based file downloads in vehicular M2M communication scenarios. The approach works on top of a standard TCP stack hence has to map identified transmission...

Network protocol changes can improve DisCom WAN performance : evaluating TCP modifications and SCTP in the ASC tri-lab environment.

Energy Technology Data Exchange (ETDEWEB)

Tolendino, Lawrence F.; Hu, Tan Chang

2005-06-01

The Advanced Simulation and Computing (ASC) Distance Computing (DisCom) Wide Area Network (WAN) is a high performance, long distance network environment that is based on the ubiquitous TCP/IP protocol set. However, the Transmission Control Protocol (TCP) and the algorithms that govern its operation were defined almost two decades ago for a network environment vastly different from the DisCom WAN. In this paper we explore and evaluate possible modifications to TCP that purport to improve TCP performance in environments like the DisCom WAN. We also examine a much newer protocol, SCTP (Stream Control Transmission Protocol) that claims to provide reliable network transport while also implementing multi-streaming, multi-homing capabilities that are appealing in the DisCom high performance network environment. We provide performance comparisons and recommendations for continued development that will lead to network communications protocol implementations capable of supporting the coming ASC Petaflop computing environments.

Molecular orientational re-ordering and the transformation of a Landau second order phase transition to first order in a nematic liquid crystal

International Nuclear Information System (INIS)

Ponce, T.C.

1988-08-01

We consider the nature of the nematic to isotropic phase transition in terms of the molecular orientational re-ordering, expressed by the variation of the order parameter, s, in the light of Landau's theory of second order phase transition. Then, we show how the de Gennes modification to the Landau thermodynamic potential converts the transition to first order which is in better agreement with the experimental observations. (author). 9 refs, 2 figs, 1 tab

Influence of the addition of β-TCP on the morphology, thermal properties and cell viability of poly (lactic acid) fibers obtained by electrospinning

Energy Technology Data Exchange (ETDEWEB)

Siqueira, L. [Laboratory of Bioceramics, Institute of Science and Technology, UNIFESP, São José dos Campos, SP (Brazil); Passador, F.R. [Laboratory of Polymer Processing, Institute of Science and Technology, UNIFESP, São José dos Campos, SP (Brazil); Costa, M.M. [Laboratory of Biomedical Nanotechnology, Development Research Institute IP& D, UNIVAP, São José dos Campos, SP (Brazil); Lobo, A.O., E-mail: aolobo@pq.cnpq.br [Laboratory of Biomedical Nanotechnology, Development Research Institute IP& D, UNIVAP, São José dos Campos, SP (Brazil); Sousa, E., E-mail: eliandra.sousa@unifesp.br [Laboratory of Bioceramics, Institute of Science and Technology, UNIFESP, São José dos Campos, SP (Brazil)

2015-07-01

Electrospinning is a simple and low-cost way to fabricate fibers. Among the various polymers used in electrospinning process, the poly (lactic acid) (PLA) stands out due to its excellent biodegradability and biocompatibility. Calcium phosphate ceramics has been recognized as an attractive biomaterial because their chemical composition is similar to the mineral component of the hard tissue in the body. Furthermore, they are bioactive and osteoinductive and some are even quite biodegradable. The beta-tricalcium phosphate (β-TCP) particles were synthesized by solid state reaction. Different contents of β-TCP particles were incorporated in polymer matrices to form fibers of PLA/β-TCP composites by electrospinning aiming a possible application as a scaffold for tissue engineering. The fibers were characterized by scanning electron microscopy (SEM), infrared (FTIR), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The average diameter of the fibers varied in the range of 260–519.6 ± 50 nm. The presence of β-TCP particles promoted changes on thermal properties of the fibers. The composite with 8 wt-% of β-TCP showed a low degree of crystallinity and can be used for application in tissue engineering. The cell viability was analyzed by reduction of the methyl tetrazolium salt by the pyruvate dehydrogenase enzymatic complex present in the matrix of mitochondria (MTT test). All PLA fiber groups, with different contents of β-TCP, showed cytocompatibility ability with non-cytotoxicity effect and bioactive properties using SBF assay. - Highlights: • PLA fibers with β-TCP particles incorporated were obtained by electrospinning aiming an application in tissue engineering.. • The average diameter of the fibers varied in the range of 260–519.6 ± 50 nm. • The composite with 8 wt.% of β-TCP showed a low degree of crystallinity and can be used for application in tissue engineering. • All PLA fibers groups, with different contents of

SU-F-T-686: Considerations About Dose Protraction Factor in TCP Calculations for Prostate VMAT Treatments

Energy Technology Data Exchange (ETDEWEB)

Clemente, F; Perez-Vara, C; Clavo, M [Herranz Hospital Central de la Defensa “Gomez Ulla”, Madrid (Spain)

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 the 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.

Comparative Efficacies of a 3D-Printed PCL/PLGA/β-TCP Membrane and a Titanium Membrane for Guided Bone Regeneration in Beagle Dogs

Directory of Open Access Journals (Sweden)

Jin-Hyung Shim

2015-10-01

Full Text Available This study was conducted to evaluate the effects of a 3D-printed resorbable polycaprolactone/poly(lactic-co-glycolic acid/β-tricalcium phosphate (PCL/PLGA/β-TCP membrane on bone regeneration and osseointegration in areas surrounding implants and to compare results with those of a non-resorbable titanium mesh membrane. After preparation of PCL/PLGA/β-TCP membranes using extrusion-based 3D printing technology; mechanical tensile testing and in vitro cell proliferation testing were performed. Implant surgery and guided bone regeneration were performed randomly in three groups (a no membrane group, a titanium membrane group, and a PCL/PLGA/β-TCP membrane group (n = 8 per group. Histological and histometric analyses were conducted to evaluate effects on bone regeneration and osseointegration. Using the results of mechanical testing; a PCL/PLGA/β-TCP ratio of 2:6:2 was selected. The new bone areas (% in buccal defects around implants were highest in the PCL/PLGA/β-TCP group and significantly higher than in the control group (p < 0.05. Bone-to-implant contact ratios (% were also significantly higher in the PCL/PLGA/β-TCP and titanium groups than in the control group (p < 0.05. When the guided bone regeneration procedure was performed using the PCL/PLGA/β-TCP membrane; new bone formation around the implant and osseointegration were not inferior to those of the non-resorbable pre-formed titanium mesh membrane.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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.

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

Science.gov (United States)

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).

Radioiodination of protein using 2,3,5,6-tetrafluorophenyl 3-(nido-carboranyl) propionate (TCP) as a potential bi-functional linker: Synthesis and biodistribution in mice

International Nuclear Information System (INIS)

Lin Rushan; Liu Ning; Yang Yuanyou; Li Bing; Liao Jiali; Jin Jiannan

2009-01-01

2,3,5,6-Tetrafluorophenyl 3-(nido-carboranyl) propionate (TCP), as a new potential bi-functional linker for radiohalogenation of proteins or peptides, was synthesized. With this bi-functional linker, the first attempt to conjugate bovine serum albumin (BSA) with 125 I was made and the biodistribution of the conjugated BSA ( 125 I-TCP-BSA) was investigated in NIH strain mice. By the use of TCP as the linker, BSA was conjugated with 125 I in a labeling yield of 58-75% and with radiochemical purity of 99.8% after purification by Sephadex TM G-50. Even after being kept at room temperature for 72 h, the radiochemical purity of 125 I-TCP-BSA was still more than 98%, much higher than that of the directly 125 I-labeled BSA ( 125 I-BSA). Meanwhile, biodistribution experiments in mice indicated that the uptake of 125 I with 125 I-TCP-BSA into thyroid was obviously less than that with 125 I-BSA post-injection. All the results implied that the 125 I-conjugated BSA ( 125 I-TCP-BSA) was considerably stable in vivo as well as in vitro, and TCP was regarded as a promising bi-functional linker for radiohalogenation of proteins

Active Queue Management in TCP Networks Based on Fuzzy-Pid Controller

Directory of Open Access Journals (Sweden)

Hossein ASHTIANI

2012-01-01

Full Text Available We introduce a novel and robust active queue management (AQM scheme based on a fuzzy controller, called hybrid fuzzy-PID controller. In the TCP network, AQM is important to regulate the queue length by passing or dropping the packets at the intermediate routers. RED, PI, and PID algorithms have been used for AQM. But these algorithms show weaknesses in the detection and control of congestion under dynamically changing network situations. In this paper a novel Fuzzy-based proportional-integral derivative (PID controller, which acts as an active queue manager (AQM for Internet routers, is proposed. These controllers are used to reduce packet loss and improve network utilization in TCP/IP networks. A new hybrid controller is proposed and compared with traditional RED based controller. Simulations are carried out to demonstrate the effectiveness of the proposed method and show that, the new hybrid fuzzy PID controller provides better performance than random early detection (RED and PID controllers

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

Science.gov (United States)

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.

Novel β-TCP/PVA bilayered hydrogels with considerable physical and bio-functional properties for osteochondral repair.

Science.gov (United States)

Yao, Hang; Kang, Junpei; Li, Weichang; Liu, Jian; Xie, Renjian; Wang, Yingjun; Liu, Sa; Wang, Dong-An; Ren, Li

2017-12-07

Cartilage repairing grafts have been widely studied, and osteochondral replacement hydrogels have proven to be an excellent method in research and clinical fields. However, it has been difficult to simultaneously solve three main issues in osteochondral replacement preparation: surface lubrication, overall mechanical support and good simulations of cell regeneration. A novel integrated bilayered hydrogel osteochondral replacement was constructed by blending polyvinyl alcohol (PVA) and β-tricalcium phosphate (β-TCP) in this study. Separated nano-ball milling with ultrasound dispersion prepared β-TCP demonstrated suitable properties of tiny particle size, high purity and ideal distribution, improving the mechanical properties of the novel integrated hydrogel, and providing a cartilage-like lubrication effect and high biocompatibility, including cytocompatibility and osteogenesis. The reinforcement of β-TCP and integrated molding technology enabled the hydrogel to demonstrate excellent component compatibility and good bonding between the two layers, which promoted the strengthening of the compression modulus and tensile modulus up to three times by mechanical testing. The surface lubrication properties of the novel osteochondral hydrogel were similar to the natural cartilage by friction coefficient characterization. The two layers of the novel integrated graft provided a considerable bio-function by co-culturing with chondrocytes and synovium mesenchymal stem cells: chondrocytes promoted adherence achieved by the upper density layer and better osteogenesis performance of the porous lower layer. The design of the bilayered β-TCP/PVA osteochondral hydrogel is promising for use in articular cartilage repair.

Nano-beta-tricalcium phosphates synthesis and biodegradation: 2. Biodegradation and apatite layer formation on nano-{beta}-TCP synthesized via microwave treatment

Energy Technology Data Exchange (ETDEWEB)

Abdel-Fattah, Wafa I; Elkhooly, Tarek A, E-mail: nrcfifi@yahoo.co [Department of Biomaterials, National Research Center, Cairo (Egypt)

2010-06-01

The degradation and/or apatite layer precipitation ability of porous {beta}-tricalcium phosphate ({beta}-TCP) samples treated and untreated with microwave radiation during synthesis is investigated. Microwave heating was used to accelerate the formation of CDHA with the Ca/P ratio 1.5 in a shorter processing time which later forms {beta}-TCP at around 650 {sup 0}C. Soaking in simulated body fluid (SBF) for several periods (4, 8, 12, 24, 36, 48, 60 and 72 h) is performed in a cumulative manner. The deposition of an apatite layer is followed through diffuse reflected FT-IR, SEM and EDS. A microwave-treated sample having a smaller particle size than its parent induces the formation of a homogeneous carbonated apatite layer on its surface. On the other hand, the parent {beta}-TCP sample exhibited less ability to induce Ca-P formation after being soaked in SBF. The formation of an apatite layer is attributed to the increase in surface area consequent to reduced particle and grain sizes besides the presence of a minor amount of hydroxyapatite phase in the microwave-treated {beta}-TCP sample. The results prove that it is possible to control the biodegradation and apatite layer formation on sintered {beta}-TCP porous disks through controlling the particle size.

ESTRATEGIA PARA EL PRONÓSTICO DEL RTO DE FAST TCP, MEDIANTE LÓGICA DIFUSA

Directory of Open Access Journals (Sweden)

Carlos Peña

2013-07-01

Full Text Available Este artículo presenta el diseño y la simulación de una estrategia para el pronóstico del temporizador de retransmisión del algoritmo de control de la congestión FAST TCP. La estrategia utiliza la técnica de inteligencia computacional denominada lógica difusa. Los resultados de la simulación demuestran que a través de esta nueva forma de pronóstico del RTO, FAST TCP hace un mejor seguimiento a la situación real de congestión de la red, en el marco de una conexión entre dos extremos de la misma.

Effect of citric acid on setting reaction and tissue response to β-TCP granular cement.

Science.gov (United States)

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.

Design and development of FPGA based TCP/IP module for real time computers in nuclear power plants

International Nuclear Information System (INIS)

Balasri, G. Janani; Santhana Raj, A.; Gour, Aditya; Murali, N.; Manikandan, J.

2013-01-01

An VME (Virtual Module Europa) bus based Real Time Computer's (RTC's) are being developed for Prototype Fast Breeder Reactor (PFBR) which is in an advanced stage of construction at Kalpakkam, where the RTC's have to communicate to the central process computer on the data collected from the field instrument and receive data from the central process computer. A Distributed Digital Control System (DDSC) architecture has been designed for this communication which is based on Transfer Communication Protocol/Internet Protocol (TCP/IP) over Ethernet. Currently the RTC's uses 'Wiznet Module', a bought out chip which implements the TCP/IP stack in hardware. This project concentrates on the design and development of Field Programmable Gate Array (FPGA) based TCP/IP module that runs on Microblaze, a 32-bit softcore processor, to take care of the communication as that of Wiznet module. Advantage of switching over to FPGA based system are its reconfigurability, desired number of sockets, and the design is stable even if the FPGA's get obsolete. (author)

Passive Mobile Bandwidth Classification Using Short Lived TCP Connections

OpenAIRE

Michelinakis, Foivos; Kreitz, Gunnar; Petrocco, Riccardo; Zhang, Boxun; Widmer, Joerg

2015-01-01

Consumption of multimedia content is moving from a residential environment to mobile phones. Optimizing Quality of Experience—smooth, quick, and high quality playback—is more difficult in this setting, due to the highly dynamic nature of wireless links. A key requirement for achieving this goal is estimating the available bandwidth of mobile devices. Ideally, this should be done quickly and with low overhead. One challenge is that the majority of connections on mobiles are short-lived TCP con...

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

International Nuclear Information System (INIS)

Anzai, Jun; Kitamura, Masahiro; Nozaki, Takenori; Nagayasu, Toshie; Terashima, Akio; Asano, Taiji; Murakami, Shinya

2010-01-01

Research highlights: → Concomitant use of FGF-2 and β-TCP (an osteo-conductive scaffold) significantly promotes periodontal regeneration in the severe periodontitis model (1-wall defect model) of beagle dog. → FGF-2 enhanced new bone formation via β-TCP at the defects. → 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. → Epithelial downgrowth (undesirable wound healing) was decreased by administration of FGF-2. → This manuscript indicates for the first time that concomitant use of FGF-2 and β-TCP is efficacious in regenerating periodontal 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 (β-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 β-TCP or β-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 β-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 β-TCP as an osteoconductive material for periodontal regeneration following severe destruction by progressive

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

Energy Technology Data Exchange (ETDEWEB)

Anzai, Jun, E-mail: anzai_jun@kaken.co.jp [Pharmacology Department, Central Research Laboratories, Kaken Pharmaceutical Co., Ltd., 14, Shinomiya, Minamigawara-cho, Yamashina-ku, Kyoto 607-8042 (Japan); Department of Periodontology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871 (Japan); Kitamura, Masahiro, E-mail: kitamura@dent.osaka-u.ac.jp [Department of Periodontology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871 (Japan); Nozaki, Takenori, E-mail: tnozaki@dent.osaka-u.ac.jp [Department of Periodontology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871 (Japan); Nagayasu, Toshie, E-mail: nagayasu_toshie@kaken.co.jp [Pharmacology Department, Central Research Laboratories, Kaken Pharmaceutical Co., Ltd., 14, Shinomiya, Minamigawara-cho, Yamashina-ku, Kyoto 607-8042 (Japan); Terashima, Akio, E-mail: terashima_akio@kaken.co.jp [Pharmacology Department, Central Research Laboratories, Kaken Pharmaceutical Co., Ltd., 14, Shinomiya, Minamigawara-cho, Yamashina-ku, Kyoto 607-8042 (Japan); Asano, Taiji, E-mail: asano_taiji@kaken.co.jp [Pharmacology Department, Central Research Laboratories, Kaken Pharmaceutical Co., Ltd., 14, Shinomiya, Minamigawara-cho, Yamashina-ku, Kyoto 607-8042 (Japan); Murakami, Shinya, E-mail: ipshinya@dent.osaka-u.ac.jp [Department of Periodontology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871 (Japan)

2010-12-17

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 periodontal 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

Structural and chemical analysis of silica-doped β-TCP ceramic coatings on surgical grade 316L SS for possible biomedical application

Directory of Open Access Journals (Sweden)

Karuppasamy Prem Ananth

2015-09-01

Full Text Available We have developed a novel approach to introduce silica-doped β-tricalcium phosphate (Si-β-TCP on 316L SS substrates for enhanced biological properties. Doping of β-TCP with silica loadings ranging from 0 to 8 mol% was carried out using chemical precipitation method. Si-β-TCP powder was sintered at 800 °C followed by coating it on 316L SS substrate using electrophoretic deposition. The coated and uncoated samples were investigated by various characterization techniques such as X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, field emission scanning electron microscopy (FESEM and X-ray fluorescence spectroscopy (XRF. Biomineralization ability of the coatings was evaluated by immersing in simulated body fluid (SBF solution for different number of days such as 7, 14, 21 and 28 days. The results obtained in our study have shown that the apatite formation ability was high for the 8 mol% of Si-β-TCP. This will promote better biomineralization ability compared to the other coatings.

A Novel HA/β-TCP-Collagen Composite Enhanced New Bone Formation for Dental Extraction Socket Preservation in Beagle Dogs

Directory of Open Access Journals (Sweden)

Ko-Ning Ho

2016-03-01

Full Text Available Past studies in humans have demonstrated horizontal and vertical bone loss after six months following tooth extraction. Many biomaterials have been developed to preserve bone volume after tooth extraction. Type I collagen serves as an excellent delivery system for growth factors and promotes angiogenesis. Calcium phosphate ceramics have also been investigated because their mineral chemistry resembles human bone. The aim of this study was to compare the performance of a novel bioresorbable purified fibrillar collagen and hydroxyapatite/β-tricalcium phosphate (HA/β-TCP ceramic composite versus collagen alone and a bovine xenograft-collagen composite in beagles. Collagen plugs, bovine graft-collagen composite and HA/β-TCP-collagen composite were implanted into the left and right first, second and third mandibular premolars, and the fourth molar was left empty for natural healing. In total, 20 male beagle dogs were used, and quantitative and histological analyses of the extraction ridge was done. The smallest width reduction was 19.09% ± 8.81% with the HA/β-TCP-collagen composite at Week 8, accompanied by new bone formation at Weeks 4 and 8. The HA/β-TCP-collagen composite performed well, as a new osteoconductive and biomimetic composite biomaterial, for socket bone preservation after tooth extraction.

New approach in subjective and objective speech transmission quality measurement in TCP/IP networks

International Nuclear Information System (INIS)

Souček, Pavel; Slavata, Oldřich; Holub, Jan

2015-01-01

This paper deals with problems of speech transmission quality measurement in modern telecommunication networks. It focuses on problems caused by specific types of distortions and errors caused present in transmissions using TCP/IP networks

A Rate-Adaptive MAC Protocol Based on TCP throughput for Ad Hoc Networks in Fading Channels

Directory of Open Access Journals (Sweden)

Shoko Uchida

2008-10-01

Full Text Available Wireless technology is becoming a leading option for future Internet access. Transmission Control Protocol (TCP is one of the protocols designed on the basis of the transmission characteristics in wired networks. It is known that the TCP performance deteriorates drastically under a wireless communication environment. On the other hand, many wireless networking standards such as IEEE 802.11a, 802.11b, and 802.11g have multirate capability. Therefore, adaptive rate control methods have been proposed for ad hoc networks. However, almost methods require the modification of the request to send (RTS and clear to send (CTS packets. Therefore, the conventional methods are not compatible with the standardized system. In this paper, we propose adaptive rate control mechanisms for ad hoc networks. Our mechanisms are based on the RTS/CTS mechanisms. However, no modifications to the RTS and CTS packets are required in the proposed method. Therefore, our proposed method can attempt to satisfy the conventional IEEE 802.11 standards. Moreover, an adequate transmission rate is selected based on an estimated TCP throughput performance. From simulation results, it is observed that the proposed method can improve the throughput performance without any modification of packet structures.

In vitro biological evaluation of beta-TCP/HDPE--A novel orthopedic composite: a survey using human osteoblast and fibroblast bone cells.

Science.gov (United States)

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 HDPE composites are biocompatible, nontoxic, and act to stimulate proliferation and adhesion of the cells, whether osteoblast or fibroblast. (c) 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008.

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

Science.gov (United States)

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.

Feasibility of TCP-based dose painting by numbers applied to a prostate case with 18F-choline PET imaging

International Nuclear Information System (INIS)

Dirscherl, Thomas; Bogner, Ludwig; Rickhey, Mark

2012-01-01

Introduction: 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. Method and Materials: 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. Results: When a TCP of 95% was aimed at, the maximal dose in a voxel of the prescription exceeded 100 Gy for most considered parameter sets. One of the parameter sets resulted in a dose range of 87.1 Gy to 99.3 Gy, 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 -1.64 Gy and a standard deviation of 4.02 Gy. Film verification showed a reasonable agreement of planned and delivered dose. Conclusion: 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. (orig.)

Analysis of SCTP and TCP based communication in high-speed clusters

International Nuclear Information System (INIS)

Kozlovszky, M.; Berceli, T.; Kutor, L.

2006-01-01

Performance and financial constraints are pushing modern DAQs (Data Acquisition Systems) to use distributed cluster environments instead of monolith one-box systems. Inside clusters application communication layers should support outstanding high performance requirements. We are currently investigating different network protocols that could meet the requirements of high speed/low latency peer-to-peer communication within DAQ clusters. We have carried out various performance measurements with TCP and SCTP over Fast and Gigabit Ethernet. We are focusing on Ethernet Technologies, because this transport medium is broad deployed, cost efficient and it has much better cost/throughput ratio than other available communication alternatives (e.g.: Myrinet, Infiniband). During this study, a protocol performance measurement application with different peer transport components has been developed. In the first part of the paper, we give a short comparison of the two protocols (SCTP and TCP), and an introduction of the transport layer structure developed. Later on we discuss the performance results of single/multi-stream peer-to-peer communication, give overview about application code transition possibilities from application developer point of view between the two protocols, and draw conclusions about usability

Effects of DCPD cement chemistry on degradation properties and cytocompatibility: comparison of MCPM/β-TCP and MCPM/HA formulations

International Nuclear Information System (INIS)

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. (paper)

SU-E-J-30: Benchmark Image-Based TCP Calculation for Evaluation of PTV Margins for Lung SBRT Patients

Energy Technology Data Exchange (ETDEWEB)

Li, M [Wayne State Univeristy, Detroit, MI (United States); Chetty, I [Henry Ford Health System, Detroit, MI (United States); Zhong, H [Henry Ford Hospital System, Detroit, MI (United States)

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 DVF 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.

SU-E-J-30: Benchmark Image-Based TCP Calculation for Evaluation of PTV Margins for Lung SBRT Patients

International Nuclear Information System (INIS)

Li, M; Chetty, I; Zhong, H

2014-01-01

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 DVF 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

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

Science.gov (United States)

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

How Equalization Techniques Affect the TCP Performance of MC-CDMA Systems in Correlated Fading Channels

Directory of Open Access Journals (Sweden)

Giacomo Leonardi

2007-12-01

Full Text Available This paper investigates the impact of several equalization techniques for multicarrier code division multiple access systems on the performance at both lower and upper layers (i.e., physical and TCP layers. Classical techniques such as maximal ratio combining, equal gain combining, orthogonality restoring combining, minimum mean square error, as well as a partial equalization (PE are investigated in time- and frequency-correlated fading channels with various numbers of interferers. Their impact on the performance at upper level is then studied. The results are obtained through an integrated simulation platform carefully reproducing all main aspects affecting the quality of service perceived by the final user, allowing an investigation of the real gain produced by signal processing techniques at TCP level.

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.

Science.gov (United States)

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.

β-TCP/HA with or without enamel matrix proteins for maxillary sinus floor augmentation

DEFF Research Database (Denmark)

Nery, James Carlos; Pereira, Luís Antônio Violin Dias; Guimarães, George Furtado

2017-01-01

BACKGROUND: It is still unclear whether enamel matrix proteins (EMD) as adjunct to bone grafting enhance bone healing. This study compared histomorphometrically maxillary sinus floor augmentation (MSFA) with β-TCP/HA in combination with or without EMD in humans. METHODS: In ten systemically healthy...

Study of Radiation Induced Radicals in HAP and β-TCP Based Bone Graft Materials by ERP Spectroscopy

International Nuclear Information System (INIS)

Maltar-Strmecki, N.; Matkovic, I.

2013-01-01

Calcium phosphates such as beta-tricalcium phosphate (β-TCP) and hydroxyapatite (HAP) are frequently used as dental implants due to proven excellent biocompatibility. Because of their resorption in the body and direct contact with tissues, in order to inactivate bacteria, fungal spores and viruses, they are usually sterilized by γ-irradiation. However, literature provides little information about effects of γ-irradiation on the formation and stability of the free radicals in the bone graft materials during and after sterilization procedure. In this study EPR (electron paramagnetic resonance) spectroscopy was used to investigate HAP and β-TCP based dental implants present on the market. Eight dental graft materials present on the market were investigated: Bioresorb R Macropore, Poresorb R -TCP, Easy-Graft T M and Cerasorb R synthetic β-tricalcium phosphates, Easy-Graft T M crystal and Ossceram R two phase synthetic CaP consisting of 60 % HAP and 40 % β-TCP, and Dexabone R and Bio-Oss R bone graft material of bovine origin. EPR study shows that this is the only technique for characterization of free radicals that can simultaneously determine not only the presence and content, but also the position and the structure of free radicals formed by γ-sterilization in the investigated materials, as well as the paramagnetic substitutions incorporated in the materials during the synthesis (such as Mn 2+ , Fe 3+ or Cr 2+ ). Additionally, EPR provides information on stability of irradiation-induced radicals (CO 2 - , trapped H-atoms, NO 3 2 etc.) and processes for reducing them. Results show that EPR should be considered as a valuable technique in improving the quality of bone graft materials, which must be sterile, and to offer the high quality, efficacy and reliable materials to the patients.(author)

Development of readout system for FE-I4 pixel module using SiTCP

Energy Technology Data Exchange (ETDEWEB)

Teoh, J.J., E-mail: jjteoh@champ.hep.sci.osaka-u.ac.jp [Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043 (Japan); Hanagaki, K. [Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka, 560-0043 (Japan); Ikegami, Y.; Takubo, Y.; Terada, S.; Unno, Y. [Institute for Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba City, Ibaraki-ken 305-0801 (Japan)

2013-12-11

The ATLAS pixel detector will be replaced in the future High Luminosity-Large Hadron Collider (HL-LHC) upgrade to preserve or improve the detector performance at high luminosity environment. To meet the tight requirements of the upgrade, a new pixel Front-End (FE) Integrated Circuit (IC) called FE-I4 has been developed. We have then devised a readout system for the new FE IC. Our system incorporates Silicon Transmission Control Protocol (SiTCP) technology (Uchida, 2008 [1]) which utilizes the standard TCP/IP and UDP communication protocols. This technology allows direct data access and transfer between a readout hardware chain and PC via a high speed Ethernet. In addition, the communication protocols are small enough to be implemented in a single Field-Programable Gate Array (FPGA). Relying on this technology, we have been able to construct a very compact, versatile and fast readout system. We have developed a firmware and software together with the readout hardware chain. We also have established basic functionalities for reading out FE-I4.

On the Behavior of ECN/RED Gateways Under a Large Number of TCP Flows: Limit Theorems

National Research Council Canada - National Science Library

Tinnakornsrisuphap, Peerapol; Makowski, Armand M

2005-01-01

.... As the number of competing flows becomes large, the asymptotic queue behavior at the gateway can be described by a simple recursion and the throughput behavior of individual TCP flows becomes asymptotically independent...

Production and characterization of chitosan/gelatin/β-TCP scaffolds for improved bone tissue regeneration

Energy Technology Data Exchange (ETDEWEB)

Serra, I.R.; Fradique, R.; Vallejo, M.C.S.; Correia, T.R.; Miguel, S.P.; Correia, I.J., E-mail: icorreia@ubi.pt

2015-10-01

Recently, bone tissue engineering emerged as a viable therapeutic alternative, comprising bone implants and new personalized scaffolds to be used in bone replacement and regeneration. In this study, biocompatible scaffolds were produced by freeze-drying, using different formulations (chitosan, chitosan/gelatin, chitosan/β-TCP and chitosan/gelatin/β-TCP) to be used as temporary templates during bone tissue regeneration. Sample characterization was performed through attenuated total reflectance-Fourier transform infrared spectroscopy, X-ray diffraction and energy dispersive spectroscopy analysis. Mechanical characterization and porosity analysis were performed through uniaxial compression test and liquid displacement method, respectively. In vitro studies were also done to evaluate the biomineralization activity and the cytotoxic profile of the scaffolds. Scanning electron and confocal microscopy analysis were used to study cell adhesion and proliferation at the scaffold surface and within their structure. Moreover, the antibacterial activity of the scaffolds was also evaluated through the agar diffusion method. Overall, the results obtained revealed that the produced scaffolds are bioactive and biocompatible, allow cell internalization and show antimicrobial activity against Staphylococcus aureus. Such, make these 3D structures as potential candidates for being used on the bone tissue regeneration, since they promote cell adhesion and proliferation and also prevent biofilm development at their surfaces, which is usually the main cause of implant failure. - Highlights: • Production of 3D scaffolds composed by chitosan/gelatin/β-TCP by freeze-drying for bone regeneration • Physicochemical characterization of the bone substitutes by SEM, FTIR, XRD and EDS • Evaluation of the cytotoxic profile and antibacterial activity of the 3D structures through in vitro assays.

Production and characterization of chitosan/gelatin/β-TCP scaffolds for improved bone tissue regeneration

International Nuclear Information System (INIS)

Serra, I.R.; Fradique, R.; Vallejo, M.C.S.; Correia, T.R.; Miguel, S.P.; Correia, I.J.

2015-01-01

Recently, bone tissue engineering emerged as a viable therapeutic alternative, comprising bone implants and new personalized scaffolds to be used in bone replacement and regeneration. In this study, biocompatible scaffolds were produced by freeze-drying, using different formulations (chitosan, chitosan/gelatin, chitosan/β-TCP and chitosan/gelatin/β-TCP) to be used as temporary templates during bone tissue regeneration. Sample characterization was performed through attenuated total reflectance-Fourier transform infrared spectroscopy, X-ray diffraction and energy dispersive spectroscopy analysis. Mechanical characterization and porosity analysis were performed through uniaxial compression test and liquid displacement method, respectively. In vitro studies were also done to evaluate the biomineralization activity and the cytotoxic profile of the scaffolds. Scanning electron and confocal microscopy analysis were used to study cell adhesion and proliferation at the scaffold surface and within their structure. Moreover, the antibacterial activity of the scaffolds was also evaluated through the agar diffusion method. Overall, the results obtained revealed that the produced scaffolds are bioactive and biocompatible, allow cell internalization and show antimicrobial activity against Staphylococcus aureus. Such, make these 3D structures as potential candidates for being used on the bone tissue regeneration, since they promote cell adhesion and proliferation and also prevent biofilm development at their surfaces, which is usually the main cause of implant failure. - Highlights: • Production of 3D scaffolds composed by chitosan/gelatin/β-TCP by freeze-drying for bone regeneration • Physicochemical characterization of the bone substitutes by SEM, FTIR, XRD and EDS • Evaluation of the cytotoxic profile and antibacterial activity of the 3D structures through in vitro assays

beta-TCP Versus Autologous Bone for Repair of Alveolar Clefts in a Goat Model.

NARCIS (Netherlands)

Ruiter, A. de; Meijer, G.J.; Dormaar, T.; Janssen, N.; Bilt, A. van der; Slootweg, P.J.; Bruijn, J. de; Rijn, L. van; Koole, R.A.

2011-01-01

Objective : The aim of this study in goats was to test the hypothesis that a novel synthetic bone substitute beta tricalcium phosphate (beta-TCP) can work as well as autologous bone harvested from the iliac crest for grafting and repair of alveolar clefts. Design : Ten adult Dutch milk goats ( Capra

Periodontal wound healing/regeneration following the application of rhGDF-5 in a beta-TCP/PLGA carrier in critical-size supra-alveolar periodontal defects in dogs.

Science.gov (United States)

Kwon, David H; Bisch, Frederick C; Herold, Robert W; Pompe, Cornelius; Bastone, Patrizia; Rodriguez, Nancy A; Susin, Cristiano; Wikesjö, Ulf M E

2010-07-01

The objective of this study was to evaluate the effect of a novel recombinant human GDF-5 (rhGDF-5) construct intended for onlay and inlay indications on periodontal wound healing/regeneration. Contralateral, surgically created, critical-size, 6-mm, supra-alveolar periodontal defects in five adult Hound Labrador mongrel dogs received rhGDF-5 coated onto beta-tricalcium phosphate (beta-TCP) particles and immersed in a bioresorbable poly(lactic-co-glycolic acid) (PLGA) composite or the beta-TCP/PLGA carrier alone (control). The rhGDF-5 and control constructs were moulded around the teeth and allowed to set. The gingival flaps were then advanced; flap margins were adapted 3-4 mm coronal to the teeth and sutured. The animals were euthanized at 8 weeks post-surgery when block biopsies were collected for histometric analysis. Healing was generally uneventful. A few sites exhibited minor exposures. Three control sites and one rhGDF-5 site (in separate animals) experienced more extensive wound dehiscencies. The rhGDF-5 and control constructs were easy to apply and exhibited adequate structural integrity to support the mucoperiosteal flaps in this challenging onlay model. Limited residual beta-TCP particles were observed at 8 weeks for both rhGDF-5/beta-TCP/PLGA and beta-TCP/PLGA control sites. The rhGDF-5/beta-TCP/PLGA sites showed significantly greater cementum (2.34 +/- 0.44 versus 1.13 +/- 0.25 mm, p=0.02) and bone (2.92 +/- 0.66 versus 1.21 +/- 0.30 mm, p=0.02) formation compared with the carrier control. Limited ankylosis was observed in four of five rhGDF-5/beta-TCP/PLGA sites but not in control sites. Within the limitations of this study, the results suggest that rhGDF-5 is a promising candidate technology in support of periodontal wound healing/regeneration. Carrier and rhGDF-5 dose optimization are necessary before further advancement of the technology towards clinical evaluation.

STUDY OF TCP PHASE PRECIPITATING IN GH4199 SUPERALLOY

Institute of Scientific and Technical Information of China (English)

T．Cui; Y．S．Zhang; S．W．Guo; L．Wang; H．C．Yang

2004-01-01

The precipitating regulation and mechanism of TCP phase (μ phase and σ phase) are studied, using electron hole number (EHN) theory, phase analysis technology and TEM observation. The results indicate that the EHN in studied alloy is 2.311-2.348 which is higher than that of critical EHN of μ phase precipitate (2.30), so μ phase could precipitate if there is enough thermo-exposition. In contrast, the calculated EHN is less than that of critical EHN of σ phase precipitate (2.52). However the σ phase is also observed by TEM.Enrich of Cr and Mo around γ phase after γ' phase precipitated leads to σ phase precipitated.

Hypo-fractionated treatment in radiotherapy: radio-biological models Tcp and NTCP; Tratamiento hipofraccionado en radioterapia: modelos radiobiologicos TCP y NTCP

Energy Technology Data Exchange (ETDEWEB)

Astudillo V, A. J.; Mitsoura, E. [Universidad Autonoma del Estado de Mexico, Facultad de Medicina, Paseo Tollocan s/n, 50180 Toluca, Estado de Mexico (Mexico); Paredes G, L. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Resendiz G, G., E-mail: lydia.paredes@inin.gob.mx [Hospital Medica Sur, Departamento de Radioterapia, Puente de Piedra 150, Col. Toriello Guerra, 14050 Mexico D. F. (Mexico)

2014-08-15

At the present time the breast cancer in Mexico has the first place of incidence of the malignant neoplasia s in the women, and represents 11.34% of all the cancer cases. On the other hand, the treatments for cancer by means of ionizing radiations have been dominated under the approaches of the medical radio-oncologists which have been based on test and error by many years. The radio-biological models, as the Tcp, NTCP and dosimetric variables, for their clinical application in the conventional radiotherapy with hypo-fractionation have as purpose predicting personalized treatment plans that they present most probability of tumor control and minor probability of late reactions, becoming this way support tools in the decisions taking for the patient treatments planning of Medical Physicists and Radio-oncologists. (Author)

Bone Regeneration Using a Mixture of Silicon-Substituted Coral HA and β-TCP in a Rat Calvarial Bone Defect Model

Directory of Open Access Journals (Sweden)

Jiyeon Roh

2016-02-01

Full Text Available 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.

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

Science.gov (United States)

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.

Modeling of twisted and coiled polymer (TCP) muscle based on phenomenological approach

Science.gov (United States)

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.

Comparison of performance between TCP/IP over ATM e ATM nativo

OpenAIRE

Marcelo Silva Freitas

2001-01-01

Com o recente desenvolvimento de tecnologias de redes de altas taxas de transmissão, tais como Asynchronous Transfer Mode (ATM), o problema da carência por largura de banda foi solucionado. A questão atual é a implementação de sistemas que suportem os protocolos ATM de forma nativa e integral. Atualmente tem-se utilizado aplicativos tradicionais baseados nos protocolos TCP(UDP)/IP no topo da pilha de protocolos ATM. Tal modelo traz redundâncias que implicam diretamente em aumento de overhead ...

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

Science.gov (United States)

Keith, B.

1994-01-01

The 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. The gateway provides the necessary mapping from one protocol to another and will facilitate practical intermachine communications in a cost effective manner by eliminating the need to standardize on a single protocol or the need to implement multiple protocols in the host computers. The purpose of the gateway is to support data transfers between application programs on different host computers using different protocols. The gateway computer must be physically connected to both host computers and must contain the system software needed to use the communication protocols of both host computers. The communication process between application partners can be divided into three phases: session establishment, data transfer, and session termination. The communication protocols supported by GATEWAY (DECnet, NETEX, and TCP/IP) have addressing mechanisms that allow an application to identify itself and distinguish among other applications on the network. The exact form of the address varies depending on whether an application is passively offering (awaiting the receipt of a network connection from another network application) or actively connecting to another network. When the gateway is started, GATEWAY reads a file of address pairs. One of the address pairs is used by GATEWAY for passively offering on one network while the other address in the pair is used for actively connecting on the other network establishing the session. Now the two application partners can send and receive data in a manner appropriate to their home networks. GATEWAY accommodates full duplex transmissions. Thus, if the application partners are sophisticated enough, they can send and receive simultaneously. GATEWAY also keeps track of the number

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

Energy Technology Data Exchange (ETDEWEB)

Roh, Hee-Sang [Department of Dental Materials, School of Dentistry, Chosun University, 309 Pilmun-daero, Dong-gu, Gwangju 61452 (Korea, Republic of); Jung, Sang-Chul [Department of Environmental Engineering, Sunchon National University, 255 Jungang-ro, Sunchon 57922 (Korea, Republic of); Kook, Min-Suk [Department of Oral and Maxillofacial Surgery, School of Dentistry, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186 (Korea, Republic of); Kim, Byung-Hoon, E-mail: kim5055@chosun.ac.kr [Department of Dental Materials, School of Dentistry, Chosun University, 309 Pilmun-daero, Dong-gu, Gwangju 61452 (Korea, Republic of)

2016-12-01

Highlights: • PLGA and PLGA/n-HAp/β-TCP scaffolds were successfully fabricated by 3D printing. • Oxygen plasma etching increases the wettability and surface roughness. • Bioceramics and oxygen plasma etching and could be used to improve the cell affinity. - Abstract: 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

The Association between State Value-added Taxes and Tobacco Use in India- Evidence from GATS and TCP India Survey.

Science.gov (United States)

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.

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

OpenAIRE

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

2017-01-01

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 ?-tricalcium phosphate (?-TCP) in a 4:4:2 ratio, PCL/PLGA/?-TCP particulate bone grafts were fabricated using 3D printing technology. Fabricated particulate bone grafts were mixed with atelocollagen to produce collagen-based PCL/P...

TCP Performance in Multi-Polling Game Theory-Based IEEE 802.11 Networks

Directory of Open Access Journals (Sweden)

Cuzanauskas Tomas

2016-12-01

Full Text Available Easy usage and integration with various applications made IEEE 802.11 one of the most used technologies these days, both at home and business premises. Over the years, there have been many additional improvements to the 802.11 standards. Nevertheless, the algorithms and Media Access Control (MAC layer methods are almost the same as in previous Wi-Fi versions. In this paper, a set of methods to improve the total system capacity is proposed – such as efficient transmit power management based on Game Theory with a custom wireless medium protocol. The transmit power management and wireless medium protocol is verified by both simulation and real application scenarios. The results conclude that the capacity of the proposed wireless medium protocol is overall 20 percent higher than the standard 802.11 wireless medium access protocols. Additional TCP Acknowledgment filtering, which was tested together with the proposed wireless medium access protocol, can provide up to 10-percent-higher TCP throughput in high-density scenarios, especially for asymmetrical traffic cases. The conducted research suggests that efficient power management could result in lighter transmit power allocation rules that are currently set by the local regulators for current Wi-Fi devices. Thus, better propagation characteristics and wireless medium management would lead to an overall higher wireless system capacity.

TINY TCP/IP PROTOCOL SUITE FOR EMBEDDED SYSTEMS WITH 32 BIT MICROCONTROLLER

OpenAIRE

Mr. Praful M. Godhankar; Mr. Maske Vishnu Dattatraya; Prof. Shahzia Sayyad

2015-01-01

The scope of embedded devices is increasing day by day and the demand will be further more when networking technology is incorporated into these devices. Many embedded systems not only communicate with each other, but also with computers using a network. All systems connected to the Internet, wireless networks such as WLAN and GPRS, and many local area networks communicate using the standard TCP/IP protocol suite. An embedded system may have as little memory, the memory constraints make progr...

A TCP/IP framework for ethernet-based measurement, control and experiment data distribution

Science.gov (United States)

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.

TCP, quantum gravity, the cosmological constant and all that .

International Nuclear Information System (INIS)

Banks, T.

1985-01-01

We study cosmology from the point of view of quantum gravity. Some light is thrown on the nature of time, and it is suggested that the cosmological arrow of time is generated by a spontaneous breakdown of TCP. Conventional cosmological models in which quantum fields interact with a time-dependent gravitational field are shown to describe an approximation to the quantum gravitational wave function which is valid in the long-wavelength limit. Two problems with initial conditions are resolved in models in which a negative bare cosmological constant is cancelled by the classical excitation of a Bose field eta with a very flat potential. These models can also give a natural explanation for the observed value of the cosmological constant. (orig.)

Long-term changes in brain following continuous phencyclidine administration: An autoradiographic study using flunitrazepam, ketanserin, mazindol, quinuclidinyl benzilate, piperidyl-3,4-3H(N)-TCP, and AMPA receptor ligands

International Nuclear Information System (INIS)

Ellison, Gaylord; Keys, Alan; Noguchi, Kevin

1999-01-01

Phencyclidine induces a model psychosis which can persist for prolonged periods and presents a strong drug model of schizophrenia. When given continuously for several days to rats, phencyclidine and other N-methyl-D-aspartate (NMDA) antagonists induce neural degeneration in a variety of limbic structures, including retrosplenial cortex, hippocampus, septohippocampal projections, and piriform cortex. In an attempt to further clarify the mechanisms underlying these degeneration patterns, autoradiographic studies using a variety of receptor ligands were conducted in animals 21 days after an identical dosage of the continuous phencyclidine administration employed in the previous degeneration studies. The results indicated enduring alterations in a number of receptors: these included decreased piperidyl-3,4- 3 H(N)-TCP (TCP), flunitrazepam, and mazindol binding in many of the limbic regions in which degeneration has been reported previously. Quinuclidinyl benzilate and (AMPA) binding were decreased in anterior cingulate and piriform cortex, and in accumbens and striatum. Piperidyl-3,4- 3 H(N)-TCP binding was decreased in most hippocampal regions. Many of these long-term alterations would not have been predicted by prior studies of the neurotoxic effects of continuous phencyclidine, and these results do not suggest a unitary source for the neurotoxicity. Whereas retrosplenial cortex, the structure which degenerates earliest, showed minimal alterations, some of the most consistent, long term alterations were in structures which evidence no immediate signs of neural degeneration, such as anterior cingulate cortex and caudate nucleus. In these structures, some of the receptor changes appeared to develop gradually (they were not present immediately after cessation of drug administration), and thus were perhaps due to changed input from regions evidencing neurotoxicity. Some of these findings, particularly in anterior cingulate, may have implications for models of

Trivalent Chromium Process (TCP) as a Sealer for MIL-A-8625F Type II, IIB, and IC Anodic Coatings

National Research Council Canada - National Science Library

Matzdorf, Craig; Beck, Erin; Hilgeman, Amy; Prado, Ruben

2008-01-01

This report documents evaluations of trivalent chromium compositions (TCP) as sealers for MIL-A-8625F Type II, IIB, and IC anodic coatings conducted from March 2001 through December 2007 by Materials Engineering...

Long-term changes in brain following continuous phencyclidine administration: An autoradiographic study using flunitrazepam, ketanserin, mazindol, quinuclidinyl benzilate, piperidyl-3,4-{sup 3}H(N)-TCP, and AMPA receptor ligands

Energy Technology Data Exchange (ETDEWEB)

Ellison, Gaylord; Keys, Alan; Noguchi, Kevin [Univ. of California Los Angeles, Dept. of Psychology, Los Angeles, CA (United States)

1999-05-01

Phencyclidine induces a model psychosis which can persist for prolonged periods and presents a strong drug model of schizophrenia. When given continuously for several days to rats, phencyclidine and other N-methyl-D-aspartate (NMDA) antagonists induce neural degeneration in a variety of limbic structures, including retrosplenial cortex, hippocampus, septohippocampal projections, and piriform cortex. In an attempt to further clarify the mechanisms underlying these degeneration patterns, autoradiographic studies using a variety of receptor ligands were conducted in animals 21 days after an identical dosage of the continuous phencyclidine administration employed in the previous degeneration studies. The results indicated enduring alterations in a number of receptors: these included decreased piperidyl-3,4-{sup 3}H(N)-TCP (TCP), flunitrazepam, and mazindol binding in many of the limbic regions in which degeneration has been reported previously. Quinuclidinyl benzilate and (AMPA) binding were decreased in anterior cingulate and piriform cortex, and in accumbens and striatum. Piperidyl-3,4-{sup 3}H(N)-TCP binding was decreased in most hippocampal regions. Many of these long-term alterations would not have been predicted by prior studies of the neurotoxic effects of continuous phencyclidine, and these results do not suggest a unitary source for the neurotoxicity. Whereas retrosplenial cortex, the structure which degenerates earliest, showed minimal alterations, some of the most consistent, long term alterations were in structures which evidence no immediate signs of neural degeneration, such as anterior cingulate cortex and caudate nucleus. In these structures, some of the receptor changes appeared to develop gradually (they were not present immediately after cessation of drug administration), and thus were perhaps due to changed input from regions evidencing neurotoxicity. Some of these findings, particularly in anterior cingulate, may have implications for models of

3D porous architecture of stacks of β-TCP granules compared with that of trabecular bone: a microCT, vector analysis and compression study

Directory of Open Access Journals (Sweden)

Daniel eCHAPPARD

2015-10-01

Full Text Available 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 β-TCP were prepared with either 12.5 or 25g 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 (resp. 69.1 ± 6.4%, p<0.05 and 0.087 ± 0.045, p<0.05 and LD bones (resp. 88.8 ± 1.57% and 0.037 ± 0.014 but exhibited a higher surface density (5.56 ± 0.11 mm2/mm3 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 trabeculae. Stacks of HP granules represent a scaffold that resembles trabecular bone in its porous microarchitecture.

[Lincomycin applied to the alveolus on TCP carrier and its effect on wound healing after surgical extraction of a third molar].

Science.gov (United States)

Wiśniewska, Izabela; Slósarczyk, Anna; Myśliwiec, Leszek; Sporniak-Tutak, Katarzyna

2009-01-01

The dental surgeon is often confronted by complications particularly after extraction ofunerupted lower third molars. The most common complication is alveolar periostitis. The healing process after extraction is accompanied by physiologic atrophy of the alveolus involving on the average 30% of bone tissue. Beta-tricalcium phosphate (TCP) is a synthetic material used in medicine to fill up bone defects caused by pathologic processes. The properties of TCP are appropriate for the material to be used as a carrier for drugs, in particular antibiotics. This study was undertaken to determine whether lincomycin applied to the alveolus on TCP carrier can be used to accelerate wound healing and reduce inflammation after surgical extraction of a third molar. We enrolled 80 patients (males and females between the age of 18 and 50 years) who underwent extraction of a third molar at the Department of Dental Surgery, Pomeranian Medical University in Szczecin. Surgical difficulty in the patients according to the Pederson scale corresponded to grade 2 or 3 (medium or high difficulty). The study group consisted of 40 patients who received lincomycin on TCP. Beta-tricalcium phosphate (300-700 microm pores) obtained from the Department of Technology of Ceramics and Refractories, AGH University of Science and Technology in Cracow, was soaked with 500 mg of lincomycin in solution and applied to the dental alveolus after tooth extraction. The alveolus was tightly sutured. The control group comprised 40 patients not treated with lincomycin. The patients reappeared for examination on the first, third, and seventh day after surgery. Attention during follow-up was directed to alveolar periostitis, pain, and trismus. Pain intensity was assessed with the 10-degree Visual Analog Scale (VAS). We analyzed the subjective pain intensity reported during follow-up by the patients. In the study group, 20 patients reported no pain 24 hours after extraction. On the third day after surgery, alveolar

Implementasi Protokol Keamanan TLS pada Aplikasi Layanan Komunikasi Suara Melalui Jaringan TCP/IP (VoIP)

OpenAIRE

Hariady, Ricky

2011-01-01

Saat ini layanan komunikasi suara melalui jaringan TCP/IP atau yang lebih dikenal dengan VoIP (Voice over IP) telah semakin banyak digunakan, namun teknologi VoIP yang ada saat ini masih rentan terhadap penyadapan ataupun pencurian data. Sementara protokol kriptografi TLS (Transport Layer Security) telah teruji dan banyak digunakan untuk mengamankan komunikasi melalui internet seperti pada layanan email dan web. Dengan mengimplementasikan protokol TLS pada sebuah aplikasi Vo...

Manufacture of β-TCP/alginate scaffolds through a Fab@home model for application in bone tissue engineering

International Nuclear Information System (INIS)

Diogo, G S; Gaspar, V M; Serra, I R; Fradique, R; Correia, I J

2014-01-01

The growing need to treat bone-related diseases in an elderly population compels the development of novel bone substitutes to improve patient quality of life. In this context, the advent of affordable and effective rapid prototyping equipment, such as the Fab@home plotter, has contributed to the development of novel scaffolds for bone tissue engineering. In this study, we report for the first time the use of a Fab@home plotter for the production of 3D scaffolds composed by beta-tricalcium phosphate (β-TCP)/alginate hybrid materials. β-TCP/alginate mixtures were used in a proportion of 50/50% (w/w), 30/70% (w/w) and 20/80% (w/w). The printing parameters were optimized to a nozzle diameter of 20 Gauge for the production of rigid scaffolds with pre-defined architectures. We observed that, despite using similar printing parameters, both the precision and resolution of the scaffolds were significantly affected by the blend's viscosity. In particular, we demonstrate that the higher viscosity of 50/50 scaffolds (150.0 ± 3.91 mPa s) provides a higher precision in the extrusion process. The physicochemical and biological characterization of the samples demonstrated that the 50/50 scaffolds possessed a resistance to compression comparable to that of native trabecular bone. Moreover, this particular formulation also exhibited a Young's modulus that was higher than that of trabecular bone. Scanning electron microscopy and fluorescence microscopy analysis revealed that osteoblasts were able to adhere, proliferate and also penetrate into the scaffold's architecture. Altogether, our findings suggest that the Fab@home printer can be employed in the manufacture of reproducible scaffolds, using a formulation 50/50 alginate-β-TCP that has suitable properties to be applied as bone substitutes in the future. (paper)

Reordenação de identidade de imigrantes árabes em Foz do Iguaçu Arabian immigrants identities reordering in Foz do Iguaçu

Directory of Open Access Journals (Sweden)

Regina Coeli Machado e Silva

2008-12-01

Full Text Available Apresentando reflexões sobre as identidades de grupos pertencentes à comunidade árabe em Foz do Iguaçu, pretende-se, neste artigo, evidenciar que ser árabe, nesse contexto, não constitui uma identidade claramente definida. Em um jogo constante de reordenação, tornando móveis seus limites, essa identidade é demarcada por diferentes significados, incluindo e excluindo esse grupo, heterogêneo, na interação local. A exclusão é visível no cultivo da língua, das religiões e nos movimentos políticos (apoio à causa palestina e a inclusão torna-se perceptível nas festas e rituais públicos. Como representações mentais, atos de percepção, de conhecimento e reconhecimento, tais identidades têm seus limites constantemente reordenados pela organização, classificação e valorização de diferentes níveis da experiência vivida neste contexto.Featuring reflections on identities of groups belonging to the Arab community in Foz do Iguaçu, it is intended, in this article, to show that being Arab, in this context, is not a clearly defined identity. In a game of constant reordering, making mobile its limitations, this identity frontier is established by different meanings, including and excluding this heterogeneous group, within the process of the local interaction. The exclusion is visible in the cultivation of language, of religions and political movements (support for the Palestinian movement and the inclusion becomes visible in public festivals and rituals. As mental representations, acts of perception, knowledge and recognition, such identities have its limits constantly reordered by the organization, classification and valuation of different levels of experience lived in this context.

An effector of apple proliferation phytoplasma targets TCP transcription factors-a generalized virulence strategy of phytoplasma?

Science.gov (United States)

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.

Carbothermic Reduction Kinetics of Phosphorous Vaporization from Tri-calcium Phosphate (TCP) Under Microwave Rapid Heating With/Without the Presence of Fe3O4

Science.gov (United States)

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.

Carbothermic Reduction Kinetics of Phosphorous Vaporization from Tri-calcium Phosphate (TCP) Under Microwave Rapid Heating With/Without the Presence of Fe3O4

Science.gov (United States)

Yoshikawa, Noboru; Sunako, Manami; Kawahira, Keita; Suzuki, Koki; Miyamoto, Kazunori; Taniguchi, Shoji

2018-03-01

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/P2O5 0 , where ΔP2O5 is the weight change and P2O5 0is 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.

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

Science.gov (United States)

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.

Bone regeneration of critical calvarial defect in goat model by PLGA/TCP/rhBMP-2 scaffolds prepared by low-temperature rapid-prototyping technology.

Science.gov (United States)

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.

Evaluation of the biotissue of PCL and β-TCP

International Nuclear Information System (INIS)

Solomao, Zenaide; Zavaglia, Cecilia A.C.

2011-01-01

The use of biomaterials to replace, repair injured tissues and organs of human beings has increased due to population growth and its higher life expectancy. The tissue engineering is an interdisciplinary field that integrates principles of biology, chemistry, genetics, materials science and biomedical engineering, to produce composite three-dimensional, capable of replacing biological tissues. The development of new biomaterials using the method of evaporation of the solvent can help to solvent this problem. This work aimed to characterized the membranes of poly (ε-caprolactone) dense and porous (scaffolds) of PCL/B-TCP; and make an in vitro evaluation. Techniques were used to: SEM, EDS, XRD, TGA, DSC, mechanical traction tests, test cell viability and activity of alkaline phosphatase (ALP). The hydrolytic degradation was analyzed in phosphate buffer (PBS) and the biocompatibility through standards (ASTM and ABNT) concluding that the materials are biocompatible and are used with great potential for replacement of the bone tissue. (author)

Influence of different naf concentration on the mechanical and morphological properties on sintered β-TCP; Estudo das propriedades mecanicas e morfologicas de [Beta]-fosfato tricalcico sinterizado com a adicao de diferentes concentracoes de NaF

Energy Technology Data Exchange (ETDEWEB)

Saito, L.; Cardoso, H.A.I.; Zavaglia, C.A.C., E-mail: liasaito89@gmail.com [Universidade Estadual de Campinas (LABIOMEC/UNICAMP), SP (Brazil); Motisuke, M. [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil)

2011-07-01

Among the bioceramics, [beta]-tricalcium phosphate, β-TCP, is currently used in biomedical applications due to its in vivo reabsorption and chemical composition, important for bone formation and repair. Researchers showed that the addition of sodium fluoride (NaF) up to 2wt.% increases β-TCP mechanical properties without altering its biocompatibility and bioactivity. In this work, the effect of different NaF concentrations (2wt.% to 5wt.%) on β-TCP properties was studied. The samples were sintered at 1250 deg C during four hours. Afterwards, it were determined its mechanical resistance, density, morphology and chemical composition as a function of NaF content. The results showed that the presence of NaF does not lead to an increase on the mechanical properties. This fact is probably related to the formation of a mixture of TCP, apatite and sodium and calcium phosphates; and a visible increase on samples' density.(author)

Proyecto Grannacional ALBASALUD para Centro Regulador de Medicamentos Esenciales de los países del ALBA-TCP Grand-national Project ALBASALUD for Regulatory Center of Essential Drugs for the ALBA-TCP countries

Directory of Open Access Journals (Sweden)

Celeste Aurora Sánchez González

2011-09-01

Full Text Available La Autoridad Reguladora de Medicamentos de Cuba, coordina un Proyecto de la Alianza Bolivariana para los pueblos de América-Tratado de Libre Comercio (ALBA-TCP, dirigido al desarrollo de un Centro Regulador para los países del ALBA como nuevo organismo regional de integración farmacéutica, en aras de contar con un Registro Grannacional válido en todos los países partes, como herramienta para facilitar el acceso a medicamentos esenciales de calidad. Esta investigación tuvo como objetivo diseñar y conducir desde el punto de vista técnico un proyecto para crear las bases legales y metodológicas del futuro centro y sus funciones básicas. Se emplearon técnicas de grupo nominal, puntos de referencia, consultas a expertos y se crearon metodologías específicas para planear y confeccionar los documentos necesarios. Se utilizaron lineamientos de organismos reguladores internacionales, cuadros básicos de medicamentos y reglamentación farmacéutica de los países participantes. Se desarrollaron y aplicaron documentos y estrategias para el trabajo del proyecto durante la etapa de preinversión, se definió el primer listado de medicamentos esenciales del ALBA y se aprobaron las fundamentales disposiciones legales y la reglamentación para las funciones de registro, vigilancia, inspecciones, laboratorios y liberación de lotes. El Proyecto Grannacional ALBASALUD "Centro Regulador de Medicamentos del ALBA-TCP" aplicado ha demostrado su eficiencia y capacidad para alcanzar los objetivos trazados mediante un trabajo científico-técnico con participación colectiva, que ha garantizado las disposiciones y lineamientos requeridos para sus funciones básicas y respaldo legal.The Drug Regulatory Authority of Cuba is coordinating a Project of the Bolivarian Alliance for the Peoples of America- Free Trade Agreement (ALBA-TCP aimed at developing a Regulatory Center that will operate as a new regional body of pharmaceutical integration for the ALBA

Optical Spectroscopy of TCP J04432130+4721280 (V392 Per) Confirms a Nova Eruption

Science.gov (United States)

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.

Use of Ethernet and TCP/IP socket communications library routines for data acquisition and control in the LEP RF system

International Nuclear Information System (INIS)

Ciapala, E.; Collier, P.; Lienard, P.

1991-01-01

A general move is being made at CERN towards the direct connection of intelligent equipment and device controllers to the control room consoles by the use of local Ethernet segments bridged to the main Token Ring networks. Communications is based on standard TCP/IP protocols which allows immediate use of standard software packages. The Data Managers which control the LEP RF accelerating units and transverse feedback systems have recently been connected. The implementation of Ethernet and TCP/IP socket communications routines for RF data acquisition and control is described. The adaptation of almost all of the existing software for RF system control, data acquisition and diagnostics to make use of this means of communication has proved straightforward. Furthermore the transparent transfer of data in the form of 'C' structures from the Data Managers to the control center workstations and other computers has considerably simplified the software required for remote surveillance and data logging with a corresponding increase in speed and reliability

Hypo-fractionated treatment in radiotherapy: radio-biological models Tcp and NTCP

International Nuclear Information System (INIS)

Astudillo V, A. J.; Mitsoura, E.; Paredes G, L.; Resendiz G, G.

2014-08-01

At the present time the breast cancer in Mexico has the first place of incidence of the malignant neoplasia s in the women, and represents 11.34% of all the cancer cases. On the other hand, the treatments for cancer by means of ionizing radiations have been dominated under the approaches of the medical radio-oncologists which have been based on test and error by many years. The radio-biological models, as the Tcp, NTCP and dosimetric variables, for their clinical application in the conventional radiotherapy with hypo-fractionation have as purpose predicting personalized treatment plans that they present most probability of tumor control and minor probability of late reactions, becoming this way support tools in the decisions taking for the patient treatments planning of Medical Physicists and Radio-oncologists. (Author)

Suboptimal RED Feedback Control for Buffered TCP Flow Dynamics in Computer Network

Directory of Open Access Journals (Sweden)

N. U. Ahmed

2007-01-01

Full Text Available We present an improved dynamic system that simulates the behavior of TCP flows and active queue management (AQM system. This system can be modeled by a set of stochastic differential equations driven by a doubly stochastic point process with intensities being the controls. The feedback laws proposed monitor the status of buffers and multiplexor of the router, detect incipient congestion by sending warning signals to the sources. The simulation results show that the optimal feedback control law from the class of linear as well as quadratic polynomials can improve the system performance significantly in terms of maximizing the link utilization, minimizing congestion, packet losses, as well as global synchronization. The optimization process used is based on random recursive search technique known as RRS.

Efficacy of rhBMP-2 loaded PCL/PLGA/β-TCP guided bone regeneration membrane fabricated by 3D printing technology for reconstruction of calvaria defects in rabbit

International Nuclear Information System (INIS)

Shim, Jin-Hyung; Jeong, Chang-Mo; Huh, Jung-Bo; Jang, Jinah; Jeong, Sung-In; Cho, Dong-Woo; Yoon, Min-Chul

2014-01-01

We successfully fabricated a three-dimensional (3D) printing-based PCL/PLGA/β-TCP guided bone regeneration (GBR) membrane that slowly released rhBMP-2. To impregnate the GBR membrane with intact rhBMP-2, collagen solution encapsulating rhBMP-2 (5 µg ml −1 ) was infused into pores of a PCL/PLGA/β-TCP membrane constructed using a 3D printing system with four dispensing heads. In a release profile test, sustained release of rhBMP-2 was observed for up to 28 d. To investigate the efficacy of the GBR membrane on bone regeneration, PCL/PLGA/β-TCP membranes with or without rhBMP-2 were implanted in an 8 mm calvaria defect of rabbits. Bone formation was evaluated at weeks 4 and 8 histologically and histomorphometrically. A space making ability of the GBR membrane was successfully maintained in both groups, and significantly more new bone was formed at post-implantation weeks 4 and 8 by rhBMP-2 loaded GBR membranes. Interestingly, implantation with rhBMP-2 loaded GBR membranes led to almost entire healing of calvaria defects within 8 weeks. (paper)

Análise de estado de tráfego de redes TCP/IP para aplicação em detecção de intrusão

OpenAIRE

Marcelo Henrique Peixoto Caetano Chaves

2002-01-01

Este trabalho apresenta o desenvolvimento de uma metodologia de reconstrução de sessões para o tráfego de redes TCP/IP. Esta metodologia baseia-se em um modelo, gerado a partir de dados extraídos do tráfego de rede, que permite reconstruir e rastrear o estado das sess~oes, utilizando apenas o cabe calho dos pacotes. Através da extrapolação do conceito de "sessão", esta modelagem permite não são reconstruir e rastrear o estado das sessões TCP, mas também reconstruir sessões ICMP e UDP. O model...

Synthesis and characterization of injectable composites of poly[D,L-lactide-co-(ε-caprolactone)] reinforced with β-TCP and CaCO3 for intervertebral disk augmentation.

Science.gov (United States)

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.

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.

Science.gov (United States)

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.

STUDY THE EFFECTIVENESS APPLICATIONS OF FUZZY CONTROLLER WITH TWO ENTRANCES IN THE SYSTEM OF ACTIVE QUEUE MANAGEMENT THE PACKETS IN TCP/IP NETWORKS

Directory of Open Access Journals (Sweden)

O. V. Nevdachyna

2016-01-01

Full Text Available The paper presents an approach to solving the overloading problem in TCP/IP networks. Offered fuzzy controller with two inputs for system of active queue management packages in TCP/IP networks, and investigated its use in these systems with a random change of traffic load. Proposed controller has two inputs, one of which is the value of the difference between the current queue length and the second – the difference between the current level of usage of the buffer. The output of the fuzzy controller calculates the probability of discarding packet.Mathematical model system of active queue management that is studied is presented in an interactive MATLAB system, in wherein also is demonstrated the processes occurring in the system with a random change of traffic load. The research results show that the AQM-system with fuzzy controller with two entrances stable enough maintains the desired current length the queue for sufficiently small values of the probability of dropping/marking packets (at acceptable size of queue q0= 200 packets, the average probability of dropping / marking is not more than 3,5×10–3 or less 0,35% packets is discarded or marked from the total number of incoming packets. The results obtained will help improve the efficiency of the functioning and operation of TCP / IP networks by increasing data transmission quality. this happens due introduction of the proposed controller at the design of new, more efficient routers for networks to minimize the delay of information.

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

Directory of Open Access Journals (Sweden)

Meng-Hsun Tsai

Full Text Available 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.

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

Science.gov (United States)

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.

WE-F-304-05: Cranial TCP/NTCP Modeling Insights and Caveats

International Nuclear Information System (INIS)

El Naqa, I.

2015-01-01

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 and 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-quadratic model

WE-F-304-05: Cranial TCP/NTCP Modeling Insights and Caveats

Energy Technology Data Exchange (ETDEWEB)

El Naqa, I. [University of Michigan (United States)

2015-06-15

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 and 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-quadratic model

The FEROL40, a microTCA card interfacing custom point-to-point links and standard TCP/IP

CERN Document Server

Gigi, Dominique; Behrens, Ulf; Branson, James; Chaze, Olivier; Cittolin, Sergio; Contescu, Cristian; da Silva Gomes, Diego; Darlea, Georgiana-Lavinia; Deldicque, Christian; Demiragli, Zeynep; Dobson, Marc; Doualot, Nicolas; Erhan, Samim; Fulcher, Jonathan Richard; Gladki, Maciej; Glege, Frank; Gomez-Ceballos, Guillelmo; Hegeman, Jeroen; Holzner, Andre; Janulis, Mindaugas; Lettrich, Michael; Meijers, Frans; Meschi, Emilio; Mommsen, Remigius K; Morovic, Srecko; O'Dell, Vivian; Orn, Samuel Johan; Orsini, Luciano; Papakrivopoulos, Ioannis; Paus, Christoph; Petrova, Petia; Petrucci, Andrea; Pieri, Marco; Rabady, Dinyar; Racz, Attila; Reis, Thomas; Sakulin, Hannes; Schwick, Christoph; Simelevicius, Dainius; Vazquez Velez, Cristina; Vougioukas, Michail; Zejdl, Petr

2017-01-01

In order to accommodate new back-end electronics of upgraded CMS sub-detectors, a new FEROL40 card in the microTCA standard has been developed. The main function of the FEROL40 is to acquire event data over multiple point-to-point serial optical links, provide buffering, perform protocol conversion, and transmit multiple TCP/IP streams (4x10Gbps) to the Ethernet network of the aggregation layer of the CMS DAQ (data acquisition) event builder. This contribution discusses the design of the FEROL40 and experience from operation.

Empirical investigation on the dependence of TCP downstream throughput on SNR in an IEEE802.11b WLAN system

Directory of Open Access Journals (Sweden)

Ikponmwosa Oghogho

2017-04-01

Full Text Available The dependence of TCP downstream throughput (TCPdownT on signal to noise ratio (SNR in an IEEE802.11b WLAN system was investigated in various environments and varieties of QoS traffic. TCPdownT was measured for various SNR observed. An Infrastructure based IEEE802.11b WLAN system having networked computers on which measurement software were installed, was set up consecutively in various environments (open corridor, small offices with block walls and plaster boards and free space. Empirical models describing TCPdownT against SNR for different signal ranges (all ranges of signals, strong signals only, grey signals only and weak signals only were statistically generated and validated. As the SNR values changed from high (strong signals through low (grey signals to very low (weak signals, our results show a strong dependence of TCPdownT on the received SNR. Our models showed lower RMS errors when compared with other similar models. We observed RMS errors of 0.6734791 Mbps, 0.472209 Mbps, 0.9111563 Mbps and 0.5764460 Mbps for general (all SNR model, strong signals model, grey signals model and Weak signals model respectively. Our models will provide researchers and WLAN systems users with a tool to estimate the TCP downstream throughput in a real network in various environments by monitoring the received SNR.

Serial Learning Process: Test of Chaining, Position, and Dual-Process Hypotheses

Science.gov (United States)

Giurintano, S. L.

1973-01-01

The chaining, position, and dual-process hypotheses of serial learning (SL) as well as serial recall, reordering, and relearning of paired-associate learning were examined to establish learning patterns. Results provide evidence for dual-process hypothesis. (DS)

INT WFC pre-discovery detection of the nova M31N 2017-11a (AT2017hvi, PTSS-17zap, TCP J00425419+4130425)

Science.gov (United States)

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).

Radiation damage, repopulation and cell recovery analysis of in vitro tumour cell megacolony culture data using a non-Poissonian cell repopulation TCP model

International Nuclear Information System (INIS)

Stavrev, P; Weldon, M; Warkentin, B; Stavreva, N; Fallone, B G

2005-01-01

The effects of radiation damage, tumour repopulation and cell sublethal damage repair and the possibility of extracting information about the model parameters describing them are investigated in this work. Previously published data on two different cultured cell lines were analysed with the help of a tumour control probability (TCP) model that describes tumour cell dynamics properly. Different versions of a TCP model representing the cases of full or partial cell recovery between fractions of radiation, accompanied by repopulation or no repopulation were used to fit the data and were ranked according to statistical criteria. The data analysis shows the importance of the linear-quadratic mechanism of cell damage for the description of the in vitro cell dynamics. In a previous work where in vivo data were analysed, the employment of the single hit model of cell kill and cell repopulation produced the best fit, while ignoring the quadratic term of cell damage in the current analysis leads to poor fits. It is also concluded that more experiments using different fractionation regimes producing diverse data are needed to help model analysis and better ranking of the models

Enhancement of Osteoblastic-Like Cell Activity by Glow Discharge Plasma Surface Modified Hydroxyapatite/β-Tricalcium Phosphate Bone Substitute

Directory of Open Access Journals (Sweden)

Eisner Salamanca

2017-11-01

Full Text Available Glow discharge plasma (GDP treatments of biomaterials, such as hydroxyapatite/β-tricalcium phosphate (HA/β-TCP composites, produce surfaces with fewer contaminants and may facilitate cell attachment and enhance bone regeneration. Thus, in this study we used argon glow discharge plasma (Ar-GDP treatments to modify HA/β-TCP particle surfaces and investigated the physical and chemical properties of the resulting particles (HA/β-TCP + Ar-GDP. The HA/β-TCP particles were treated with GDP for 15 min in argon gas at room temperature under the following conditions: power: 80 W; frequency: 13.56 MHz; pressure: 100 mTorr. Scanning electron microscope (SEM observations showed similar rough surfaces of HA/β-TCP + Ar-GDP HA/β-TCP particles, and energy dispersive spectrometry analyses showed that HA/β-TCP surfaces had more contaminants than HA/β-TCP + Ar-GDP surfaces. Ca/P mole ratios in HA/β-TCP and HA/β-TCP + Ar-GDP were 1.34 and 1.58, respectively. Both biomaterials presented maximal intensities of X-ray diffraction patterns at 27° with 600 a.u. At 25° and 40°, HA/β-TCP + Ar-GDP and HA/β-TCP particles had peaks of 200 a.u., which are similar to XRD intensities of human bone. In subsequent comparisons, MG-63 cell viability and differentiation into osteoblast-like cells were assessed on HA/β-TCP and HA/β-TCP + Ar-GDP surfaces, and Ar-GDP treatments led to improved cell growth and alkaline phosphatase activities. The present data indicate that GDP surface treatment modified HA/β-TCP surfaces by eliminating contaminants, and the resulting graft material enhanced bone regeneration.

Software Switching for High Throughput Data Acquisition Networks

CERN Document Server

AUTHOR|(CDS)2089787; Lehmann Miotto, Giovanna

The bursty many-to-one communication pattern, typical for data acquisition systems, is particularly demanding for commodity TCP/IP and Ethernet technologies. The problem arising from this pattern is widely known in the literature as \\emph{incast} and can be observed as TCP throughput collapse. It is a result of overloading the switch buffers, when a specific node in a network requests data from multiple sources. This will become even more demanding for future upgrades of the experiments at the Large Hadron Collider at CERN. It is questionable whether commodity TCP/IP and Ethernet technologies in their current form will be still able to effectively adapt to bursty traffic without losing packets due to the scarcity of buffers in the networking hardware. This thesis provides an analysis of TCP/IP performance in data acquisition networks and presents a novel approach to incast congestion in these networks based on software-based packet forwarding. Our first contribution lies in confirming the strong analogies bet...

Patterned Fibers Embedded Microfluidic Chips Based on PLA and PDMS for Ag Nanoparticle Safety Testing

Directory of Open Access Journals (Sweden)

Yaowen Liu

2016-11-01

Full Text Available A new method to integrate poly-dl-lactide (PLA patterned electrospun fibers with a polydimethylsiloxane (PDMS microfluidic chip was successfully developed via lithography. Hepatocyte behavior under static and dynamic conditions was investigated. Immunohistochemical analyses indicated good hepatocyte survival under the dynamic culture system with effective hepatocyte spheroid formation in the patterned microfluidic chip vs. static culture conditions and tissue culture plate (TCP. In particular, hepatocytes seeded in this microfluidic chip under a flow rate of 10 μL/min could re-establish hepatocyte polarity to support biliary excretion and were able to maintain high levels of albumin and urea secretion over 15 days. Furthermore, the optimized system could produce sensitive and consistent responses to nano-Ag-induced hepatotoxicity during culture. Thus, this microfluidic chip device provides a new means of fabricating complex liver tissue-engineered scaffolds, and may be of considerable utility in the toxicity screening of nanoparticles.

WE-F-304-02: Recurrent HNC Treated with SBRT: TCP-Based Outcome Estimates

International Nuclear Information System (INIS)

Clump, D.

2015-01-01

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 and 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-quadratic model

WE-F-304-02: Recurrent HNC Treated with SBRT: TCP-Based Outcome Estimates

Energy Technology Data Exchange (ETDEWEB)

Clump, D. [University of Pittsburgh Medical Center (United States)

2015-06-15

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 and 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-quadratic model

Uso de novos materiais para o capeamento pulpar (hidroxiapatita - HAp e fosfato tricálcico - β-TCP The use of new materials for pulp capping (hydroxyapatite - HAp and tricalcium phosphate - β-TCP

Directory of Open Access Journals (Sweden)

C. S. Delfino

2010-12-01

Full Text Available O capeamento pulpar é uma medida importante e muito usada no cotidiano da prática odontológica e, quando realizado de forma consciente, baseado em um bom diagnóstico da condição pulpar no momento da exposição, pode prevenir o dente de sofrer uma intervenção endodôntica. Além do hidróxido de cálcio, outros materiais vêm sendo testados quanto a sua ação em promover o reparo pulpar pela formação de ponte de dentina, após capeamento pulpar direto. Uma das alternativas de materiais viáveis para o capeamento pulpar são as cerâmicas à base de fosfatos de cálcio, destacando-se a hidroxiapatita (HAp e o fosfato tricálcico (β-TCP. Estes materiais não promovem a formação de área necrótica, característica da utilização do hidróxido de cálcio, são biocompatíveis e favorecem o reparo do tecido pulpar. Para avaliar os efeitos desses materiais no capeamento pulpar foi realizada esta revisão de literatura, abordando desde a resposta do tecido pulpar, até o protocolo para o uso clínico.Pulp capping is an important measure and one with a high rate of use in daily dental practice, and when it is conscientiously performed, based on good diagnosis of the pulp condition at the time of its exposure, it may prevent the tooth from requiring endodontic intervention. In addition to calcium hydroxide, other materials have been tested with regard to their action in promoting pulp repair by the formation of a dentin bridge after direct pulp capping. Some of the feasible alternative materials for pulp capping are calcium phosphate-based ceramics, with hydroxyapatite (HAp and tricalcium phosphate (β-TCP being outstanding. These materials do not promote formation of a necrotic area, characteristic of the use of calcium hydroxide, are biocompatible and favor pulp tissue repair. To evaluate the effects of these materials on pulp capping, this literature review was conducted, the approach being wide ranging in scope, from pulp response

Visual analytics of geo-social interaction patterns for epidemic control.

Science.gov (United States)

Luo, Wei

2016-08-10

Human interaction and population mobility determine the spatio-temporal course of the spread of an airborne disease. This research views such spreads as geo-social interaction problems, because population mobility connects different groups of people over geographical locations via which the viruses transmit. Previous research argued that geo-social interaction patterns identified from population movement data can provide great potential in designing effective pandemic mitigation. However, little work has been done to examine the effectiveness of designing control strategies taking into account geo-social interaction patterns. To address this gap, this research proposes a new framework for effective disease control; specifically this framework proposes that disease control strategies should start from identifying geo-social interaction patterns, designing effective control measures accordingly, and evaluating the efficacy of different control measures. This framework is used to structure design of a new visual analytic tool that consists of three components: a reorderable matrix for geo-social mixing patterns, agent-based epidemic models, and combined visualization methods. With real world human interaction data in a French primary school as a proof of concept, this research compares the efficacy of vaccination strategies between the spatial-social interaction patterns and the whole areas. The simulation results show that locally targeted vaccination has the potential to keep infection to a small number and prevent spread to other regions. At some small probability, the local control strategies will fail; in these cases other control strategies will be needed. This research further explores the impact of varying spatial-social scales on the success of local vaccination strategies. The results show that a proper spatial-social scale can help achieve the best control efficacy with a limited number of vaccines. The case study shows how GS-EpiViz does support the design

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

Energy Technology Data Exchange (ETDEWEB)

Balderson, M.J.; Kirkby, C. [Department of Physics and Astronomy, University of Calgary, Calgary, Alberta (Canada); Department of Medical Physics, Tom Baker Cancer Centre, Calgary, Alberta (Canada); Department of Medical Physics, Jack Ady Cancer Centre, Lethbridge, Alberta (Canada)

2014-08-15

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 changing 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.

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

International Nuclear Information System (INIS)

Balderson, M.J.; Kirkby, C.

2014-01-01

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 changing 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

Application of the distributed genetic algorithm for loading pattern optimization problems

International Nuclear Information System (INIS)

Hashimoto, Hiroshi; Yamamoto, Akio

2000-01-01

The distributed genetic algorithm (DGA) is applied for loading pattern optimization problems of the pressurized water reactors (PWR). Due to stiff nature of the loading pattern optimizations (e.g. multi-modality and non-linearity), stochastic methods like the simulated annealing or the genetic algorithm (GA) are widely applied for these problems. A basic concept of DGA is based on that of GA. However, DGA equally distributes candidates of solutions (i.e. loading patterns) to several independent 'islands' and evolves them in each island. Migrations of some candidates are performed among islands with a certain period. Since candidates of solutions independently evolve in each island with accepting different genes of migrants from other islands, premature convergence in the traditional GA can be prevented. Because many candidate loading patterns should be evaluated in one generation of GA or DGA, the parallelization in these calculations works efficiently. Parallel efficiency was measured using our optimization code and good load balance was attained even in a heterogeneous cluster environment due to dynamic distribution of the calculation load. The optimization code is based on the client/server architecture with the TCP/IP native socket and a client (optimization module) and calculation server modules communicate the objects of loading patterns each other. Throughout the sensitivity study on optimization parameters of DGA, a suitable set of the parameters for a test problem was identified. Finally, optimization capability of DGA and the traditional GA was compared in the test problem and DGA provided better optimization results than the traditional GA. (author)

Function-Based Algorithms for Biological Sequences

Science.gov (United States)

Mohanty, Pragyan Sheela P.

2015-01-01

Two problems at two different abstraction levels of computational biology are studied. At the molecular level, efficient pattern matching algorithms in DNA sequences are presented. For gene order data, an efficient data structure is presented capable of storing all gene re-orderings in a systematic manner. A common characteristic of presented…

A New Method for Fabrication of Nanohydroxyapatite and TCP from the Sea Snail Cerithium vulgatum

Directory of Open Access Journals (Sweden)

O. Gunduz

2014-01-01

Full Text Available Biphasic bioceramic nanopowders of hydroxyapatite (HA and β-tricalcium phosphate (TCP were prepared from shells of the sea snail Cerithium vulgatum (Bruguière, 1792 using a novel chemical method. Calcination of the powders produced was carried out at varying temperatures, specifically at 400°C and 800°C, in air for 4 hours. When compared to the conventional hydrothermal transformation method, this chemical method is very simple, economic, due to the fact that it needs inexpensive and safe equipment, because the transformation of the aragonite and calcite of the shells into the calcium phosphate phases takes place at 80°C under the atmospheric pressure. The powders produced were determined using infrared spectroscopy (FT-IR, X-ray diffraction, and scanning electron microscopy (SEM. The features of the powders produced along with the fact of their biological origin qualify these powders for further consideration and experimentation to fabricate nanoceramic biomaterials.

Cyber Security in Industrial Control Systems and SCADA Applications: Modbus TCP Protocol Example

Directory of Open Access Journals (Sweden)

Erdal IRMAK

2017-12-01

Full Text Available Electrical energy generation, transmission and distribution systems are evaluated in terms of national security dimension and defined as critical infrastructures. Monitoring and controlling of these systems is provided by Industrial Control Systems (ICS or Supervisory Control and Data Acquisition (SCADA systems. According to the latest advances in communication and internet technology, ICS/SCADA systems have started to become integrated with these systems. As a result of this situation, current or existing vulnerabilities in information and communication technology affect to SCADA systems directly. Therefore, this paper focuses on the cyber security of ICS/SCADA systems. It has been proved that the lack of authentication detected in Modbus TCP protocol, one of the most used in ICS/SCADA systems, can be exploited. In order to solve this security issue, a software is developed using the Python programming language for blocking or mitigating the cyber attacks. The proposed solution is subjected to several tests and results show that the attacks can be prevented successfully. Thus, it is considered that the proposed work will contribute to the security of ICS/SCADA systems and the industrial protocols using for communicating these systems.

Diseño e implementación de un algoritmo para translación de protocolo entre las normas IEC60870-5-104 y MODBUS TCP/IP

OpenAIRE

Feria Briceño, John Henry; Universidad Distrital Francisco José de Caldas

2015-01-01

Este artículo muestra los resultados del proceso de diseño, implementación y prueba de un algoritmo para hacer la translación de protocolo entre las normas IEC 60870-5-104 y MODBUS TCP/IP, éste modelo de algoritmos son de amplio uso en los procesos de supervisión y automatización en sub-estaciones eléctricas.

Proposal for the award of a contract for the supply of TCP and TCS collimators for the LHC

CERN Document Server

2004-01-01

This document concerns the award of a contract for the supply of 40 TCP and TCS collimators for the LHC cleaning insertions. The Finance Committee is invited to agree to the negotiation of a contract with CERCA (FR), the lowest bidder, for the supply of 40 collimators for a total amount of 1 122 173 euros (1 718 720 Swiss francs), not subject to revision, with options for up to 11 collimators for an amount of up to 279 280 euros (427 745 Swiss francs), subject to revision for inflation from 1 January 2007, bringing the total amount to 1 401 453 euros (2 146 465 Swiss francs), subject to revision for inflation from 1 January 2007. The rate of exchange used is that stipulated in the tender.

Pandemic serotypes of Vibrio cholerae isolated from ships' ballast tanks and coastal waters: assessment of antibiotic resistance and virulence genes (tcpA and ctxA).

Science.gov (United States)

Dobbs, Fred C; Goodrich, Amanda L; Thomson, Frank K; Hynes, Wayne

2013-05-01

There is concern that ships' ballasting operations may disseminate Vibrio cholerae to ports throughout the world. Given evidence that the bacterium is indeed transported by ships, we isolated pandemic serotypes O1 and O139 from ballast tanks and characterized them with respect to antibiotic resistance and virulence genes ctxA and tcpA. We carried out concurrent studies with V. cholerae isolated from coastal waters. Of 284 isolates, 30 were serotype O1 and 59 were serotype O139. These serotypes were overrepresented in ballast tanks relative to the coastal waters sampled. All locations, whether coastal waters or ballast tanks, yielded samples from which serotype O1, O139, or both were isolated. There were three groups among the 62 isolates for which antibiotic characterization was conclusive: those exhibiting β-lactamase activity and resistance to at least one of the 12 antibiotics tested; those negative for β-lactamase but having antibiotic resistance; those negative for β-lactamase and registering no antibiotic resistance. When present, antibiotic resistance in nearly all cases was to ampicillin; resistance to multiple antibiotics was uncommon. PCR assays revealed that none of the isolates contained the ctxA gene and only two isolates, one O139 and one O1, contained the tcpA gene; both isolates originated from ballast water. These results support the bacteriological regulations proposed by the International Maritime Association for discharged ballast water.

EFECTO DE LOS OBSTÁCULOS TIPO POLIMERO RESINA EN RENDIMIENTO DE REDES TCP/IP/IEEE 802.11g MODO AD-HOC

OpenAIRE

Márquez Barriobero, David

2011-01-01

La investigación tiene como objetivo primordial el desarrollo de un modelo matemático para evaluar el efecto de los obstáculos de tipo polímero resina en el rendimiento de redes TCP/IP/IEEE 802.11g modo ad-hoc; esto con el propósito de establecer la relación existente entre el diámetro de los obstáculos de tipo polímero resina y el rendimiento de una red inalámbrica en modo ad-hoc, al transmitir datos vía protocolo FTP. El tipo de investigación es explicativa con un diseño experimental. Los t...

Clinical implications of alternative TCP models for nonuniform dose distributions

International Nuclear Information System (INIS)

Deasy, J. O.

1995-01-01

Several tumor control probability (TCP) models for nonuniform dose distributions were compared, including: (a) a logistic/inter-patient-heterogeneity model, (b) a probit/inter-patient-heterogeneity model, (c) a Poisson/radioresistant-strain/identical-patients model, (d) a Poisson/inter-patient-heterogeneity model and (e) a Poisson/intra-tumor- and inter-patient-heterogeneity model. The models were analyzed in terms of the probability of controlling a single tumor voxel (the voxel control probability, or VCP), as a function of voxel volume and dose. Alternatively, the VCP surface can be thought of as the effect of a small cold spot. The models based on the Poisson equation which include inter-patient heterogeneity ((d) and (e)) have VCP surfaces (VCP as a function of dose and volume) which have a threshold 'waterfall' shape: below the waterfall (in dose), VCP is nearly zero. The threshold dose decreases with decreasing voxel volume. However, models (a), (b), and (c) all show a high probability of controlling a voxel (VCP>50%) with very low dose (e.g., 1 Gy) if the voxel is small (smaller than about 10 -3 of the tumor volume). Model (c) does not have the waterfall shape at low volumes due to the assumption of patient uniformity and a neglect of the effect of the clonogens which are more radiosensitive (and more numerous). Models (a) and (b) deviate from the waterfall shape at low volumes due to numerical differences between the functions used and the Poisson function. Hence, the Possion models which include inter-patient heterogeneities ((d) and (e)) are more sensitive to the effects of small cold spots than the other models considered

Robotic hand with locking mechanism using TCP muscles for applications in prosthetic hand and humanoids

Science.gov (United States)

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.

Polyvalent fuel treatment facility (TCP): shearing and dissolution of used fuel at La Hague facility

Energy Technology Data Exchange (ETDEWEB)

Brueziere, J.; Tribout-Maurizi, A.; Durand, L.; Bertrand, N. [Recycling Business Unit, AREVA, 1 place de la coupole, 92084 Paris La defense Cedex (France)

2013-07-01

Although many used nuclear fuel types have already been recycled, recycling plants are generally optimized for Light Water Reactor (LWR) UO{sub x} fuel. Benefits of used fuel recycling are consequently restricted to those fuels, with only limited capacity for the others like LWR MOX, Fast Reactor (FR) MOX or Research and Test Reactor (RTR) fuel. In order to recycle diverse fuel types, an innovative and polyvalent shearing and dissolving cell is planned to be put in operation in about 10 years at AREVA's La Hague recycling plant. This installation, called TCP (French acronym for polyvalent fuel treatment) will benefit from AREVA's industrial feedback, while taking part in the next steps towards a fast reactor fuel cycle development using innovative treatment solutions. Feasibility studies and R/Development trials on dissolution and shearing are currently ongoing. This new installation will allow AREVA to propose new services to its customers, in particular in term of MOX fuel, Research Test Reactors fuel and Fast Reactor fuel treatment. (authors)

Rapid-prototyped PLGA/β-TCP/hydroxyapatite nanocomposite scaffolds in a rabbit femoral defect model

International Nuclear Information System (INIS)

Kim, Jinku; McBride, Sean; Alvarez-Urena, Pedro; Song, Young-Hye; Hollinger, Jeffrey O; Tellis, Brandi; Dean, David D; Sylvia, Victor L; Elgendy, Hoda; Ong, Joo

2012-01-01

Bone tissue engineering scaffolds composed of poly(d,l-lactide:glycolide) (DL-PLGA) and β-tricalcium phosphate (β-TCP) nanocomposites were prepared and characterized. Scaffolds with two specific architectures were produced via fused deposition modeling (FDM), a type of extrusion freeform fabrication. Microfilaments deposited at angles of 0° and 90° were designated as the ‘simple’ scaffold architecture, while those deposited at angles alternating between 0°, 90°, 45° and −45° were designated as the ‘complex’ scaffold architecture. In addition, the simple and complex scaffolds were coated with hydroxyapatite (HA). The surface morphology of the scaffolds was assessed before and after HA coating and uniform distribution of HA coating on the surface was observed by scanning electron microscopy. The scaffolds were implanted into rabbit femoral unicortical bone defects according to four treatment groups based on pore structure and HA coating. After 6 and 12 weeks, scaffolds and host bone were recovered and processed for histology. Data suggest that all configurations of the scaffolds integrated with the host bone and were biocompatible and thus may offer an exciting new scaffold platform for delivery of biologicals for bone regeneration. (paper)

Real time data acquisition for a time projection chamber using a high speed DEC-RT11 to UNIX UDP-TCP/IP interface

International Nuclear Information System (INIS)

Thomas, J.; Douglas, M.; Watanabe, R.; Henrikson, H.E.; Iqbal, M.Z.; Mitchell, L.W.; O'Callaghan, B.M.G.; Wong, H.T.K.; Melvin, J.D.

1987-01-01

The authors built a high pressure xenon Time Projection Chamber to study double beta decay, a process of fundamental interest which, if observed, would indicate that the neutrino is a massive Majorana particle. Raw data rates from the TPC exceed 200 Kbytes per second. The TPC is operated through a CAMAC interface with a DEC LSI-11/73 computer networked to a Tektronix 6130 workstation. Data is transmitted at about 15 Kbytes per second although the network is capable of transmitting data at 80 Kbytes per second. The only system level programming required was to write a UDP-TCP/IP driver for the DEC-DEQNA Ethenet board on the 11/73

Mechanism of enhanced conversion of 1,2,3-trichloropropane by mutant haloalkane dehalogenase revealed by molecular modeling

Science.gov (United States)

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.

α-TCP cements prepared by syringe-foaming: Influence of Na2HPO4 and surfactant concentration.

Science.gov (United States)

Vásquez, A F; Domínguez, S; Loureiro Dos Santos, L A

2017-12-01

The lack of intrinsic open porosity in calcium phosphate cements slows down the resorption rate and bone ingrowth when implanted In Vivo. In this study, macroporous structures were obtained by mixing α-TCP cement with a foamed liquid phase containing different concentrations of sodium hydrogen phosphate and a nonionic surfactant. The cement paste was prepared by hand mixing in a novel system of two syringes connected by a tube. Two different liquid to powder (L/P) ratios were used to prepare the cement paste. The cement samples showed open macropores with diameters>100μm. The specimens prepared with lower L/P ratio showed smaller porosity, macroporosity and pore size distribution. The cohesion of the cement paste in liquid solutions was assessed by adding 2wt% sodium alginate to the liquid phase. This study suggests that the final macrostructure of the foamed cements can be controlled by varying the phosphate and surfactant concentrations in the liquid phase and the L/P ratio. Copyright © 2017 Elsevier B.V. All rights reserved.

Study on mineral components of rat calvaria by means of X-ray powder diffraction analysis and Raman microprobe spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Tamura, Norihiro [Meikai Univ., Sakado, Saitama (Japan). School of Dentistry

2000-07-01

The present study was designed to examine the occurrence of the precursor minerals of hydroxyapatite (HA) during the process of HA formation in the rat calvaria. Dried and powdered rat calvaria and synthetic samples, such as HA, dicalcium phosphate dihydrate (DCPD), octacalcium phosphate (OCP), ({beta}-calcium pyrophosphate) and ({beta}-tricalcium phosphate), were used. Determinations were carried out by X-ray powder diffraction and Raman microprobe spectrometry. In general, significant widening of the diffraction peaks was shown to occur after the plasma ashing was performed for the X-ray diffraction. As a result, two adjacent peaks seen normally in the diffraction angles (2 {theta}) 30-35 deg, which is a characteristic feature of HA, were found to fuse with each other, forming a widened single peak. Also, there was a tendency for the intensity of the diffraction peaks to increase with age. With regard to the effect of plasma ashing on the crystallograms of synthetic specimens, all specimens manifested sharp peak patterns except DCPD and OCP. In contrast, a widening of diffraction peaks was observed in the DCPD and OCP samples, indicating that crystallinity had changed during the pretreatment. Results obtained from both vital and synthetic samples after heat treatment at 1000 deg C were as follow: Clearcut diffraction patterns, characteristics of HA, were obtained in all of the calvaria samples. Further, {beta}-TCP was produced by heat treatment of OCP, and its pattern was detected in the samples from rats younger than 6 days of age. Amounts of {beta}-TCP in percentage were disclosed to be 40.2% in embryonal samples, 28.4% in newborn samples, and 18.6% in 6-day-old samples. But no {beta}-TCP could be detected in the 12-week-old samples, indicating that the amount of {beta}-TCP in calvaria decreased with age. We also found that ashing pretreatment did not cause any changes in the samples of HA, {beta}-CPP, and {beta}-TCP. Further, DCPD and {beta}-CPP samples shared

Study on mineral components of rat calvaria by means of X-ray powder diffraction analysis and Raman microprobe spectroscopy

International Nuclear Information System (INIS)

Tamura, Norihiro

2000-01-01

The present study was designed to examine the occurrence of the precursor minerals of hydroxyapatite (HA) during the process of HA formation in the rat calvaria. Dried and powdered rat calvaria and synthetic samples, such as HA, dicalcium phosphate dihydrate (DCPD), octacalcium phosphate (OCP), (β-calcium pyrophosphate) and (β-tricalcium phosphate), were used. Determinations were carried out by X-ray powder diffraction and Raman microprobe spectrometry. In general, significant widening of the diffraction peaks was shown to occur after the plasma ashing was performed for the X-ray diffraction. As a result, two adjacent peaks seen normally in the diffraction angles (2 θ) 30-35 deg, which is a characteristic feature of HA, were found to fuse with each other, forming a widened single peak. Also, there was a tendency for the intensity of the diffraction peaks to increase with age. With regard to the effect of plasma ashing on the crystallograms of synthetic specimens, all specimens manifested sharp peak patterns except DCPD and OCP. In contrast, a widening of diffraction peaks was observed in the DCPD and OCP samples, indicating that crystallinity had changed during the pretreatment. Results obtained from both vital and synthetic samples after heat treatment at 1000 deg C were as follow: Clearcut diffraction patterns, characteristics of HA, were obtained in all of the calvaria samples. Further, β-TCP was produced by heat treatment of OCP, and its pattern was detected in the samples from rats younger than 6 days of age. Amounts of β-TCP in percentage were disclosed to be 40.2% in embryonal samples, 28.4% in newborn samples, and 18.6% in 6-day-old samples. But no β-TCP could be detected in the 12-week-old samples, indicating that the amount of β-TCP in calvaria decreased with age. We also found that ashing pretreatment did not cause any changes in the samples of HA, β-CPP, and β-TCP. Further, DCPD and β-CPP samples shared the same diffraction pattern, and OCP

Analysis of the influence of two different milling processes in the properties of precursor powder and [Beta]-TCP cement

International Nuclear Information System (INIS)

Cardoso, H.A.I.; Pereira, C.H.R.; Zavaglia, C.A.C.; Motisuke, M.

2011-01-01

There are several characteristics that put calcium phosphate cements in evidence, like its bioactivity and in vivo resorption. The influence of two milling processes in the morphological properties of the [beta]-tricalcium phosphate powder, [beta]-TCP, and in the mechanical properties of the cement were analyzed. The powder was obtained by solid state reaction of CaCO_3 and CaHPO_4 at 1050 ° C. It showed high phase purity and absence of toxic elements. The powder was processed in ball mill (A) and high-energy vibratory mill (B), with posterior analyze by SEM and particle size distribution. The powders showed different average and distribution of grain size. Finally, the cement obtained by the process (B) showed values of axial tensile strength significantly greater than that obtained by the process (A). The milling process (B) is much more efficient than the process (A). (author)

On the use of biomathematical models in patient-specific IMRT dose QA

Energy Technology Data Exchange (ETDEWEB)

Zhen Heming [UT Southwestern Medical Center, Dallas, Texas 75390 (United States); Nelms, Benjamin E. [Canis Lupus LLC, Merrimac, Wisconsin 53561 (United States); Tome, Wolfgang A. [Department of Radiation Oncology, Division of Medical Physics, Montefiore Medical Center and Institute of Onco-Physics, Albert Einstein College of Medicine, Bronx, New York 10461 (United States)

2013-07-15

Purpose: To investigate the use of biomathematical models such as tumor control probability (TCP) and normal tissue complication probability (NTCP) as new quality assurance (QA) metrics.Methods: Five different types of error (MLC transmission, MLC penumbra, MLC tongue and groove, machine output, and MLC position) were intentionally induced to 40 clinical intensity modulated radiation therapy (IMRT) patient plans (20 H and N cases and 20 prostate cases) to simulate both treatment planning system errors and machine delivery errors in the IMRT QA process. The changes in TCP and NTCP for eight different anatomic structures (H and N: CTV, GTV, both parotids, spinal cord, larynx; prostate: CTV, rectal wall) were calculated as the new QA metrics to quantify the clinical impact on patients. The correlation between the change in TCP/NTCP and the change in selected DVH values was also evaluated. The relation between TCP/NTCP change and the characteristics of the TCP/NTCP curves is discussed.Results:{Delta}TCP and {Delta}NTCP were summarized for each type of induced error and each structure. The changes/degradations in TCP and NTCP caused by the errors vary widely depending on dose patterns unique to each plan, and are good indicators of each plan's 'robustness' to that type of error.Conclusions: In this in silico QA study the authors have demonstrated the possibility of using biomathematical models not only as patient-specific QA metrics but also as objective indicators that quantify, pretreatment, a plan's robustness with respect to possible error types.

On the use of biomathematical models in patient-specific IMRT dose QA

International Nuclear Information System (INIS)

Zhen Heming; Nelms, Benjamin E.; Tomé, Wolfgang A.

2013-01-01

Purpose: To investigate the use of biomathematical models such as tumor control probability (TCP) and normal tissue complication probability (NTCP) as new quality assurance (QA) metrics.Methods: Five different types of error (MLC transmission, MLC penumbra, MLC tongue and groove, machine output, and MLC position) were intentionally induced to 40 clinical intensity modulated radiation therapy (IMRT) patient plans (20 H and N cases and 20 prostate cases) to simulate both treatment planning system errors and machine delivery errors in the IMRT QA process. The changes in TCP and NTCP for eight different anatomic structures (H and N: CTV, GTV, both parotids, spinal cord, larynx; prostate: CTV, rectal wall) were calculated as the new QA metrics to quantify the clinical impact on patients. The correlation between the change in TCP/NTCP and the change in selected DVH values was also evaluated. The relation between TCP/NTCP change and the characteristics of the TCP/NTCP curves is discussed.Results:ΔTCP and ΔNTCP were summarized for each type of induced error and each structure. The changes/degradations in TCP and NTCP caused by the errors vary widely depending on dose patterns unique to each plan, and are good indicators of each plan's “robustness” to that type of error.Conclusions: In this in silico QA study the authors have demonstrated the possibility of using biomathematical models not only as patient-specific QA metrics but also as objective indicators that quantify, pretreatment, a plan's robustness with respect to possible error types

Experimental Evaluation of TCP-Based DTN for Cislunar Communications in Presence of Long Link Disruption

Directory of Open Access Journals (Sweden)

Zhang Zhensheng

2011-01-01

Full Text Available Delay/disruption tolerant networking (DTN technology is considered a new solution to highly stressed communications in space environments. To date, little work has been done in evaluating the effectiveness and performance of the available DTN protocols when they are applied to an interplanetary Internet, especially in presence of a long link disruption. In this paper, we present an experimental investigation of the DTN architecture with a Bundle Protocol (BP running over TCP-based convergence layer (TCPCL protocol in a simulated cislunar communication environment characterized by a long link disruption. The intent of this work is to investigate the effectiveness of the TCPCL-based DTN protocol in coping with long link disruptions, through realistic file transfer experiments using a PC-based test-bed. The experiment results show that the DTN protocol is effective in handling a long link disruption experienced in data transmission accompanied by a cislunar link delay and a high BER. The performance of the DTN is most adversely affected by link disruption time in comparison to the effect of link delay and BER. For the transmissions with a very long link disruption of hours, the variations in goodput are nominal with respect to the change in cislunar link delay.

Electron beam induced oxygen disordering in YBa2Cu3O7-x superconductors

International Nuclear Information System (INIS)

Basu, S.N.; Roy, T.; Mitchell, T.E.; Nastasi, M.

1990-01-01

Thin foils of bulk YBa 2 Cu 3 O 7-x (YBCO) superconductors were subjected to electron irradiation in a transmission electron microscope (TEM). The resulting disordering of the oxygen atoms and vacancies in the Cu-O planes was monitored by measuring the splitting of the (110) diffraction spots in the [001] diffraction pattern. Samples were irradiated at 83 K with 100, 150, 200 and 300 kV electrons. The 100 kV electrons did not cause any disordering, even after prolonged irradiation. The results of the higher energy irradiations showed an excellent fit to a disordering model, indicating a lack of radiation assisted reordering at 83 K. This was further confirmed by the insensitivity of the disordering to the dose rate of 300 kV electrons at 83 K. However, at 300 K, an increase in the dose rate of 300 kV electrons increased the disordering rate, indicating that radiation assisted reordering was occurring at that temperature

Efficacy of Ganoderma sp. JAS4 in bioremediation of chlorpyrifos and its hydrolyzing metabolite TCP from agricultural soil.

Science.gov (United States)

Silambarasan, Sivagnanam; Abraham, Jayanthi

2014-01-01

A novel fungal strain JAS4 was isolated from agricultural soil and was found to be highly effective in degrading chlorpyrifos and its major degradation product 3,5,6-trichloro-2-pyridinol (TCP). The molecular characterization based on 18S rRNA sequence analysis, revealed strain JAS4 as Ganoderma sp. which could able to degrade chlorpyrifos and its metabolite in an aqueous medium with rate constant of 0.8460 day(-1), following first order rate kinetics, and the time in which the initial insecticide concentration was reduced by 50% (DT(50)) was 0.81 days. Studies on biodegradation in soil with nutrients showed that JAS4 strain exhibited efficient degradation of insecticide with a rate constant of 0.9 day(-1), and DT(50) was 0.73 day. In contrast, degradation of insecticide in soil without nutrients was characterized by a rate constant of 0.7576 day(-1) and the DT(50) was 0.91 day. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Feature Selection by Reordering

Czech Academy of Sciences Publication Activity Database

Jiřina, Marcel; Jiřina jr., M.

2005-01-01

Roč. 2, č. 1 (2005), s. 155-161 ISSN 1738-6438 Institutional research plan: CEZ:AV0Z10300504 Keywords : feature selection * data reduction * ordering of features Subject RIV: BA - General Mathematics

A bottom-up model of spatial attention predicts human error patterns in rapid scene recognition.

Science.gov (United States)

Einhäuser, Wolfgang; Mundhenk, T Nathan; Baldi, Pierre; Koch, Christof; Itti, Laurent

2007-07-20

Humans demonstrate a peculiar ability to detect complex targets in rapidly presented natural scenes. Recent studies suggest that (nearly) no focal attention is required for overall performance in such tasks. Little is known, however, of how detection performance varies from trial to trial and which stages in the processing hierarchy limit performance: bottom-up visual processing (attentional selection and/or recognition) or top-down factors (e.g., decision-making, memory, or alertness fluctuations)? To investigate the relative contribution of these factors, eight human observers performed an animal detection task in natural scenes presented at 20 Hz. Trial-by-trial performance was highly consistent across observers, far exceeding the prediction of independent errors. This consistency demonstrates that performance is not primarily limited by idiosyncratic factors but by visual processing. Two statistical stimulus properties, contrast variation in the target image and the information-theoretical measure of "surprise" in adjacent images, predict performance on a trial-by-trial basis. These measures are tightly related to spatial attention, demonstrating that spatial attention and rapid target detection share common mechanisms. To isolate the causal contribution of the surprise measure, eight additional observers performed the animal detection task in sequences that were reordered versions of those all subjects had correctly recognized in the first experiment. Reordering increased surprise before and/or after the target while keeping the target and distractors themselves unchanged. Surprise enhancement impaired target detection in all observers. Consequently, and contrary to several previously published findings, our results demonstrate that attentional limitations, rather than target recognition alone, affect the detection of targets in rapidly presented visual sequences.

Mechanism of magnetic recovery in the disorder-order transformation of Fe70Al30 mechanically deformed alloys

International Nuclear Information System (INIS)

Rodriguez, D. Martin; Apinaniz, E.; Plazaola, F.; Garitaonandia, J.S.; Jimenez, J.A.; Schmool, D.S.; Cuello, G.J.

2005-01-01

The degree of order in Fe-Al intermetallic alloys has an important influence on their magnetic properties. Moreover, the deformation of ordered alloys causes a dramatic increase of magnetization. If deformed alloys are heated, their magnetic properties decrease again. The reordering process was monitored by neutron diffraction, Moessbauer spectroscopy, and calorimetric measurements on the Fe 70 Al 30 crushed alloy. This indicates that the reordering process occurs in two stages. In the first (150-200 deg. C) new small B2 phase domains are nucleated due to vacancy migration. A second reordering stage occurs between 300 and 450 deg. C, where dislocation motion induces B2 domain growth and A2 phase elimination. The main mechanism responsible for this decrease of magnetization during the reordering process is the decrease of the disordered A2 phase content in the alloy

A discriminative syntactic model for source permutation via tree transduction

NARCIS (Netherlands)

Khalilov, M.; Sima'an, K.; Wu, D.

2010-01-01

A major challenge in statistical machine translation is mitigating the word order differences between source and target strings. While reordering and lexical translation choices are often conducted in tandem, source string permutation prior to translation is attractive for studying reordering using

The growth of stem cells within {beta}-TCP scaffolds in a fluid-dynamic environment

Energy Technology Data Exchange (ETDEWEB)

Xu Shanglong [School of Mechatronics Engineering, University of Electronic Science and Technology, Chengdu (China); State Key Laboratory of Mechanical Manufacture System Engineering, Xi' an Jiaotong University, Xi' an (China); Li Dichen [State Key Laboratory of Mechanical Manufacture System Engineering, Xi' an Jiaotong University, Xi' an (China)], E-mail: dcli@mail.xjtu.edu.cn; Xie Youzhuan; Lu Jianxi; Dai Kerong [Department of Orthopaedic Surgery, Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai (China)

2008-01-10

A three-dimensional dynamic perfusion system was developed to provide mass transport and nutrient supply to permit the cell proliferation during the long-term culture inside a {beta}-tricalcium phosphate ({beta}-TCP) scaffold. Also the flow field throughout the scaffold was studied. The porous cylindrical scaffold with a central channel was seeded with the sheep mesenchymal stem cells (MSCs). Then the cell-seeded scaffolds were continuously perfused with the complete {alpha}-MEM medium by a peristaltic pump for 7, 14 and 28 days, respectively. Histological study showed that the cell proliferation rates were different throughout the whole scaffolds and the different cell coverage was shown in different positions of the scaffold. Unoccupied spaces were found in many macropores. A computational fluid dynamics (CFD) modeling was used to simulate the flow conditions within perfused cell-seeded scaffolds to give an insight into the mechanisms of these cell growth phenomena. Relating the simulation results to perfusion experiments, the even fluid velocity (approximately 0.52 mm/s) and shear stress (approximately 0.0055 Pa) were found to correspond to increased cell proliferation within the cell-scaffold constructs. Flow speeds were between 0.25 and 0.75 mm/s and shear stresses were between 0.003 and 0.008 Pa in approximately 75% of the regions. This method exhibits novel capabilities to compare the results obtained for different perfusion rates or different scaffold microarchitectures. It may allow specific fluid velocities and shear stresses to be determined to optimize the perfusion flow rate, porous scaffold architecture and distribution of in vitro tissue growth.

The growth of stem cells within β-TCP scaffolds in a fluid-dynamic environment

International Nuclear Information System (INIS)

Xu Shanglong; Li Dichen; Xie Youzhuan; Lu Jianxi; Dai Kerong

2008-01-01

A three-dimensional dynamic perfusion system was developed to provide mass transport and nutrient supply to permit the cell proliferation during the long-term culture inside a β-tricalcium phosphate (β-TCP) scaffold. Also the flow field throughout the scaffold was studied. The porous cylindrical scaffold with a central channel was seeded with the sheep mesenchymal stem cells (MSCs). Then the cell-seeded scaffolds were continuously perfused with the complete α-MEM medium by a peristaltic pump for 7, 14 and 28 days, respectively. Histological study showed that the cell proliferation rates were different throughout the whole scaffolds and the different cell coverage was shown in different positions of the scaffold. Unoccupied spaces were found in many macropores. A computational fluid dynamics (CFD) modeling was used to simulate the flow conditions within perfused cell-seeded scaffolds to give an insight into the mechanisms of these cell growth phenomena. Relating the simulation results to perfusion experiments, the even fluid velocity (approximately 0.52 mm/s) and shear stress (approximately 0.0055 Pa) were found to correspond to increased cell proliferation within the cell-scaffold constructs. Flow speeds were between 0.25 and 0.75 mm/s and shear stresses were between 0.003 and 0.008 Pa in approximately 75% of the regions. This method exhibits novel capabilities to compare the results obtained for different perfusion rates or different scaffold microarchitectures. It may allow specific fluid velocities and shear stresses to be determined to optimize the perfusion flow rate, porous scaffold architecture and distribution of in vitro tissue growth

Impact of different synthetic bone fillers on healing of extraction sockets: an experimental study in dogs.

Science.gov (United States)

Hong, Ji-Youn; Lee, Jung-Seok; Pang, Eun-Kyoung; Jung, Ui-Won; Choi, Seong-Ho; Kim, Chong-Kwan

2014-02-01

The objective of this study was to elucidate the socket healing process and biodegradation of incorporating synthetic bone fillers followed by grafting of the fresh extraction socket. Third premolars in four quadrants of eight beagle dogs were extracted and randomly treated with either one of hydroxyapatite (HA), biphasic calcium phosphate (BCP), β-tricalcium phosphate (β-TCP), or no graft (C). Histologic observations and histomorphometric analysis at three zones (apical, middle, and coronal) of the socket were performed. Socket area (S) and the proportions of newly formed bone (%NB), residual biomaterials (%RB), and fibrovascular connective tissue (%FCT) at 2, 4, and 8 weeks were measured. The numbers of osteoclast-like multinucleated cells (No.OC) were also determined at the three zones. %NB was significantly higher in control group compared with the grafted groups at all healing periods. %NB of HA and BCP increased with time, whereas %RB showed different patterns that decreased in BCP, unlike the minimal change observed in HA. %NB of β-TCP showed smallest portion compared with other grafted groups at 2 and 4 weeks, however, significantly increased at 8 weeks. %RB of β-TCP was less than HA and BCP at all healing periods. Numbers of multinucleated cells were greater in BCP and β-TCP, followed by HA and smallest in control group. Within the limit of this study, bone formation of the extraction socket was delayed in the sockets grafted with synthetic bone fillers and showed different healing process according to the biodegradation patterns. © 2012 John Wiley & Sons A/S.

Biphasic calcium phosphates (BCP of hydroxyapatite (HA and tricalcium phosphate (TCP as bone substitutes: Importance of physicochemical characterizations in biomaterials studies

Directory of Open Access Journals (Sweden)

Mehdi Ebrahimi

2017-02-01

Full Text Available The data presented in this article are related to the research article entitled “Biphasic calcium phosphates bioceramics (HA/TCP: Concept, physicochemical properties and the impact of standardization of study protocols in biomaterials research” [1]. This article provides in depth study of BCP bone substitutes as valuable option in the field of tissue engineering. However, there are discrepancies in the literature regarding the ideal physicochemical properties of BCP and the ideal balance between different phase compositions for enhanced bone tissue engineering (M. Ebrahimi, M.G. Botelho, S.V. Dorozhkin, 2016; M. Ebrahimi, P. Pripatnanont, S. Suttapreyasri, N. Monmaturapoj, 2014 [1,2]. This is found to be mainly because of improper characterization of BCP bioceramics in basic studies and lack of standard study protocols in in vitro and in vivo research. This data article along with original article provide the basic data required for ideal characterization of BCP and other bioceramics in an attempt to provide basic standardized protocols for future studies.

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

Energy Technology Data Exchange (ETDEWEB)

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. 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.

Calibration of robot tool centre point using camera-based system

Directory of Open Access Journals (Sweden)

Gordić Zaviša

2016-01-01

Full Text Available Robot Tool Centre Point (TCP calibration problem is of great importance for a number of industrial applications, and it is well known both in theory and in practice. Although various techniques have been proposed for solving this problem, they mostly require tool jogging or long processing time, both of which affect process performance by extending cycle time. This paper presents an innovative way of TCP calibration using a set of two cameras. The robot tool is placed in an area where images in two orthogonal planes are acquired using cameras. Using robust pattern recognition, even deformed tool can be identified on images, and information about its current position and orientation forwarded to control unit for calibration. Compared to other techniques, test results show significant reduction in procedure complexity and calibration time. These improvements enable more frequent TCP checking and recalibration during production, thus improving the product quality.

Investigating a reduced size real-time transport protocol for low-bandwidth networks

CSIR Research Space (South Africa)

Kakande, JN

2011-09-01

Full Text Available in this work as RTP-Lite, requires investigation. A cyclical approach to compression of the RTP headers was used with different compression cycle patterns for Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) transport. Measurements over...

Are laboratory tests always needed? Frequency and causes of laboratory overuse in a hospital setting.

Science.gov (United States)

Cadamuro, Janne; Gaksch, Martin; Wiedemann, Helmut; Lippi, Giuseppe; von Meyer, Alexander; Pertersmann, Astrid; Auer, Simon; Mrazek, Cornelia; Kipman, Ulrike; Felder, Thomas K; Oberkofler, Hannes; Haschke-Becher, Elisabeth

2018-04-01

Inappropriate utilization of laboratory resources is an increasing concern especially in high-throughput facilities. Until now, no reliable information has been published addressing to which extent laboratory results are actually used for clinical decision-making. Therefore, we aimed to close this gap using a novel retrospective approach including a survey of clinicians and nurses. We retrospectively evaluated the number of re-orders for potassium (K), lactate dehydrogenase (LD), aspartate-aminotransferase (AST), activated partial thromboplastin-time (APTT) and prothrombin-time/INR (PT/INR), after the initial order had to be cancelled due to preanalytical non-conformities. We analyzed subgroups regarding time to re-order, ward and sample priority (urgent vs. routine). Subsequently, we surveyed clinicians and nurses, asking for their estimate of the amount of failed re-orders as well as for possible reasons. From initially cancelled tests, only ~20% of K, LD, AST and ~30% of APTT and PT/INR tests were re-ordered within 24 h. 70% of the investigated clinical chemistry and 60% of coagulation tests were re-ordered one week after cancellation or not at all. Survey participants quite accurately estimated these numbers. Routine laboratory panels, short stay of out-patients, obsolete test results and avoiding additional phlebotomies were the main reasons for not re-ordering cancelled tests. Overall, 60-70% of test results in the investigated assays ordered in a high throughput laboratory are potentially inappropriate or of doubtful clinically importance. Although clinicians and nurses are aware of this situation, it is the duty of laboratory specialists to overcome overutilization in close collaboration with all involved healthcare workers. Copyright © 2018 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Ethernet TCP/IP based building energy management system in a university campus in Saudi Arabia

Energy Technology Data Exchange (ETDEWEB)

Jomoah, Ibrahim M. [Department of Industrial Engineering, King Abdulaziz University Jeddah-21589 (Saudi Arabia); Kumar, R. Sreerama; Abdel-Shafi, Nabil Yassien [Saudi Electricity Company Chair for DSM and EE, Vice Presidency for Projects, King Abdulaziz University Jeddah 21589 (Saudi Arabia); Al-Abdulaziz, Abdulaziz Uthman M.; Obaid, Ramzy R. [Department of Electrical and Computer Engineering, King Abdulaziz University Jeddah-21589 (Saudi Arabia)

2013-07-01

This paper investigates the effectiveness of the Building Energy Management System (BMS) installed in the typical buildings in the main campus of King Abdulaziz University, Jeddah, in Saudi Arabia. As the domestic electricity and hence the oil consumption in Saudi Arabia is increasing at a very alarming rate compared to the other countries in the world, it is of paramount importance to resort to urgent measures in various industrial, commercial and residential sectors in the country to implement energy conservation measures. The major electrical load in the buildings in the University corresponds to air-handling units and lighting. If the Hajj period, during which millions of pilgrims visit Holy Makah, coincides with the summer, the electricity demand in the country further increases. Considering these issues, the university has taken initiatives to minimize energy consumption in the campuses through the various energy conservation measures. Towards this end, BMS is installed in a few of the typical classrooms and office buildings utilizing the existing campus Ethernet TCP/IP. The data analysis is performed over the period from April to September as it is the peak load period due to summer season. The effectiveness of the BMS in the minimization of the energy consumption in these buildings is established by comparing the results of data analysis with BMS against those before the installation of BMS over the peak period. The investigations reveal that appreciable saving in energy consumption can be achieved with the installation of BMS, the magnitude being dependent upon factors such as building characteristics, type of building, its utilization and period of use.

Antiferromagnetic ordering states of oxygen-deficient NdBa₂Cu₃O_6+x and Nd_1+yBa_2-yCu₃O_6+x single crystals

DEFF Research Database (Denmark)

Brecht, E.; Schweiss, P.; Wolf, T.

1999-01-01

The paper describes a study of the antiferromagnetic ordering of oxygen-deficient Nd1 + yBa2 - yCu3O6 + x single crystals. In pure, stoichiometric samples, y = 0, with different oxygen contents x in the Cu(1) plane (0.02AFI) phase appears to be stable down to 316 m...... of this reordering suggests that the Nd3+ ions on Ba sites are very effective defects forcing the AFIAFII reordering. The mechanism of reordering is explained in terms of the creation of Cu2+ moments within the Cu(1) layer due to the Nd3+ ions on Ba sites, which via polarization lead to an effective ferromagnetic...

Chlorella vulgaris cultivation in sludge extracts from 2,4,6-TCP wastewater treatment for toxicity removal and utilization.

Science.gov (United States)

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.

SU-F-J-187: The Statistical NTCP and TCP Models in the Proton Therapy

Energy Technology Data Exchange (ETDEWEB)

Jang, S [Princeton Radiation Oncology, Princeton Radiation Oncology (United States); Frometa, T [Theoretical and Computational Methods Working Group of IMAG, Santiago de Cuba (Cuba); Pyakuryal, A [National Cancer Institute, Rockville, MD (United States); Sio, T [MD Anderson Cancer Center, Houston, TX (United States); Piseaux, R [Northwestern University, Chicago, IL (United States); Acosta, S [Provincial Hospital of Santiago de Cuba, Santiago de Cuba (Cuba); Ocana, K [Faculty of Electrics of the University of Oriente, Santiago de Cuba (Cuba)

2016-06-15

Purpose: The statistical models (SM) are typically used as a subjective description of a population for which there is only limited sample data, and especially in cases where the relationship between variables is known. The normal tissue complications and tumor control are frequently stochastic effects in the Radiotherapy (RT). Based on probabilistic treatments, it recently has been formulated new NTCP and TCP models for the RT. Investigating the particular requirements for their clinical use in the proton therapy (PT) is the goal of this work. Methods: The SM can be used as phenomenological or mechanistic models. The former way allows fitting real data and getting theirparameters. In the latter one, we should do efforts for determining the parameters through the acceptable estimations, measurements, and/or simulation experiments. Experimental methodologies for determination of the parameters have been developed from the fraction cells surviving the proton irradiation curves in tumor and OAR, and precise RBE models are used for calculating the variable of effective dose. As the executions of these methodologies have a high costs, so we have developed computer tools enable to perform simulation experiments as complement to limitations of the real ones. Results: The requirements for the use of the SM in the PT, such as validation and improvement of the elaborated and existent methodologies for determining the SM parameters and effective dose respectively, were determined. Conclusion: The SM realistically simulates the main processes in the PT, and for this reason these can be implemented in this therapy, which are simples, computable and they have other advantages over some current models. It has been determined some negative aspects for some currently used probabilistic models in the RT, like the LKB NTCP and others derived from logistic functions; which can be improved with the proposed methods in this study.

Reordering Histology to Enhance Engagement

Science.gov (United States)

Amerongen, Helen

2011-01-01

In redesigning the preclinical curriculum and shifting from a discipline-based approach to an organ system-based approach, faculty at the University of Arizona College of Medicine in Tucson took the opportunity to restructure the sequence of introductory histology content to make it more engaging and relevant. In this article, the author describes…

Occurrence in Mexico, 1998-2008, of Vibrio cholerae CTX+ El Tor carrying an additional truncated CTX prophage.

Science.gov (United States)

Alam, Munirul; Rashed, Shah Manzur; Mannan, Shahnewaj Bin; Islam, Tarequl; Lizarraga-Partida, Marcial Leonardo; Delgado, Gabriela; Morales-Espinosa, Rosario; Mendez, Jose Luis; Navarro, Armando; Watanabe, Haruo; Ohnishi, Makoto; Hasan, Nur A; Huq, Anwar; Sack, R Bradley; Colwell, Rita R; Cravioto, Alejandro

2014-07-08

The seventh cholera pandemic caused by Vibrio cholerae O1 El Tor (ET) has been superseded in Asia and Africa by altered ET possessing the cholera toxin (CTX) gene of classical (CL) biotype. The CL biotype of V. cholerae was isolated, along with prototypic and altered ET, during the 1991 cholera epidemic in Mexico and subsequently remained endemic until 1997. Microbiological, molecular, and phylogenetic analyses of clinical and environmental V. cholerae isolated in Mexico between 1998 and 2008 revealed important genetic events favoring predominance of ET over CL and altered ET. V. cholerae altered ET was predominant after 1991 but not after 2000. V. cholerae strains isolated between 2001 and 2003 and a majority isolated in 2004 lacked CTX prophage (Φ) genes encoding CTX subunits A and B and repeat sequence transcriptional regulators of ET and CL biotypes: i.e., CTXΦ(-). Most CTXΦ(-) V. cholerae isolated in Mexico between 2001 and 2003 also lacked toxin coregulated pili tcpA whereas some carried either tcpA(ET) or a variant tcpA with noticeable sequence dissimilarity from tcpA(CL). The tcpA variants were not detected in 2005 after CTXΦ(+) ET became dominant. All clinical and environmental V. cholerae O1 strains isolated during 2005-2008 in Mexico were CTXΦ(+) ET, carrying an additional truncated CTXΦ instead of RS1 satellite phage. Despite V. cholerae CTXΦ(-) ET exhibiting heterogeneity in pulsed-field gel electrophoresis patterns, CTXΦ(+) ET isolated during 2004-2008 displayed homogeneity and clonal relationship with V. cholerae ET N16961 and V. cholerae ET isolated in Peru.

Distributed open environment for data retrieval based on pattern recognition techniques

International Nuclear Information System (INIS)

Pereira, A.; Vega, J.; Castro, R.; Portas, A.

2010-01-01

Pattern recognition methods for data retrieval have been applied to fusion databases for the localization and extraction of similar waveforms within temporal evolution signals. In order to standardize the use of these methods, a distributed open environment has been designed. It is based on a client/server architecture that supports distribution, interoperability and portability between heterogeneous platforms. The server part is a single desktop application based on J2EE (Java 2 Enterprise Edition), which provides a mature standard framework and a modular architecture. It can handle transactions and concurrency of components that are deployed on JETTY, an embedded web container within the Java server application for providing HTTP services. The data management is based on Apache DERBY, a relational database engine also embedded on the same Java based solution. This encapsulation allows hiding of unnecessary details about the installation, distribution, and configuration of all these components but with the flexibility to create and allocate many databases on different servers. The DERBY network module increases the scope of the installed database engine by providing traditional Java database network connections (JDBC-TCP/IP). This avoids scattering several database engines (a unique embedded engine defines the rules for accessing the distributed data). Java thin clients (Java 5 or above is the unique requirement) can be executed in the same computer than the server program (for example a desktop computer) but also server and client software can be distributed in a remote participation environment (wide area networks). The thin client provides graphic user interface to look for patterns (entire waveforms or specific structural forms) and display the most similar ones. This is obtained with HTTP requests and by generating dynamic content (servlets) in response to these client requests.

Distributed Open Environment for Data Retrieval based on Pattern Recognition Techniques

Energy Technology Data Exchange (ETDEWEB)

Pereira, A.; Vega, J.; Castro, R.; Portas, A. [Association EuratomCIEMAT para Fusion, Madrid (Spain)

2009-07-01

Full text of publication follows: Pattern recognition methods for data retrieval have been applied to fusion databases for the localization and extraction of similar waveforms within temporal evolution signals. In order to standardize the use of these methods, a distributed open environment has been designed. It is based on a client/server architecture that supports distribution, inter-operability and portability between heterogeneous platforms. The server part is a single desktop application based on J2EE, which provides a mature standard framework and a modular architecture. It can handle transactions and competition of components that are deployed on JETTY, an embedded web container within the Java server application for providing HTTP services. The data management is based on Apache DERBY, a relational database engine also embedded on the same Java based solution. This encapsulation allows concealment of unnecessary details about the installation, distribution, and configuration of all these components but with the flexibility to create and allocate many databases on different servers. The DERBY network module increases the scope of the installed database engine by providing traditional Java database network connections (JDBC-TCP/IP). This avoids scattering several database engines (a unique embedded engine defines the rules for accessing the distributed data). Java thin clients (Java 5 or above is the unique requirement) can be executed in the same computer than the server program (for example a desktop computer) but also server and client software can be distributed in a remote participation environment (wide area networks). The thin client provides graphic user interface to look for patterns (entire waveforms or specific structural forms) and display the most similar ones. This is obtained with HTTP requests and by generating dynamic content (servlets) in response to these client requests. (authors)

Distributed open environment for data retrieval based on pattern recognition techniques

Energy Technology Data Exchange (ETDEWEB)

Pereira, A., E-mail: augusto.pereira@ciemat.e [Asociacion EURATOM/CIEMAT para Fusion, CIEMAT, Edificio 66, Avda. Complutense, 22, 28040 Madrid (Spain); Vega, J.; Castro, R.; Portas, A. [Asociacion EURATOM/CIEMAT para Fusion, CIEMAT, Edificio 66, Avda. Complutense, 22, 28040 Madrid (Spain)

2010-07-15

Pattern recognition methods for data retrieval have been applied to fusion databases for the localization and extraction of similar waveforms within temporal evolution signals. In order to standardize the use of these methods, a distributed open environment has been designed. It is based on a client/server architecture that supports distribution, interoperability and portability between heterogeneous platforms. The server part is a single desktop application based on J2EE (Java 2 Enterprise Edition), which provides a mature standard framework and a modular architecture. It can handle transactions and concurrency of components that are deployed on JETTY, an embedded web container within the Java server application for providing HTTP services. The data management is based on Apache DERBY, a relational database engine also embedded on the same Java based solution. This encapsulation allows hiding of unnecessary details about the installation, distribution, and configuration of all these components but with the flexibility to create and allocate many databases on different servers. The DERBY network module increases the scope of the installed database engine by providing traditional Java database network connections (JDBC-TCP/IP). This avoids scattering several database engines (a unique embedded engine defines the rules for accessing the distributed data). Java thin clients (Java 5 or above is the unique requirement) can be executed in the same computer than the server program (for example a desktop computer) but also server and client software can be distributed in a remote participation environment (wide area networks). The thin client provides graphic user interface to look for patterns (entire waveforms or specific structural forms) and display the most similar ones. This is obtained with HTTP requests and by generating dynamic content (servlets) in response to these client requests.

Study and realisation of a gateway between a MIL1553 network and an Ethernet network. Implementation of the OS9NET homogeneous network and of the TCP/IP heterogeneous network on the OS-9/68000 real time operating system

International Nuclear Information System (INIS)

Tricot-Censier, Pascal

1989-01-01

This research thesis addresses the design of a homogeneous network for machines acquiring data in real time, and the interconnection by a heterogeneous network of this group with three groups of mini-computers, workstations, and personal computers. Thus, this work involved hardware as well as software designs and developments. After a recall of main notions related to networks, and a presentation of the OS9 real time core, the author reports the design and development of the Ethernet controller card. He reports the design and realisation of a gateway between Ethernet and MIL1553 which is notably based on the previously mentioned controller card. An Ethernet driver is then designed for the OS9 operating system. As the connection with other machines which do not support OS9, requires the development of applications using TCP/IP protocols, the author describes how software designed for PCs have been adapted for a use in real time and for the OS9 operating system. He presents an additional software layer to TCP/IP for an inter-process communication through a heterogeneous network. This layer allows the development of applications distributed among systems which possess different processors and operating systems. Finally, the author presents a test protocol which ensures the fast transfer of memory blocks between OS9 machines [fr

The effect of microwave and conventional heating on a modified sol-gel derived biphasic calcium phosphate

Science.gov (United States)

Herradi, S.; Bouhazma, S.; Khaldi, M.; El Hachadi, A.; El Bali, B.; Lachkar, M.

2018-03-01

A facile sol-gel method was used to synthesize either hydroxyapatite (HA) or beta-tricalcium phosphate (β-TCP) as the major phase. Herein, we report, on the one hand, the effect of a very low maturation temperature on the final powder composition after drying step, and on the other hand, we compare the effect of calcination of this powder by microwave or electric furnace. It was found that microwave heating has led to the formation of hydroxyapatite phase upon 180°C for 20 minutes, however, XRD patterns show that the powder becomes less crystallized upon 220°C and amorphous upon 230°C. In contrast, furnace heating at 600°C and 700°C converts the as-synthesized powder to β-TCP as the major phase together with HA as the minor phase. This work shows the possibility to obtain the as-prepared BCP at much lower maturation temperature; it also gives an insight into the role, of either microwave or conventional heating, in controlling the ratio between HA and β-TCP in the sintered powder.

Characterization and in vitro evaluation of biphasic α-tricalcium phosphate/β-tricalcium phosphate cement

Energy Technology Data Exchange (ETDEWEB)

Arahira, Takaaki; Maruta, Michito, E-mail: maruta@college.fdcnet.ac.jp; Matsuya, Shigeki

2017-05-01

Biphasic calcium phosphate consisting of hydroxyapatite (HA) and β-tricalcium phosphate(β-TCP) is an excellent bone substitute with controllable bioresorbability. Fabrication of biphasic calcium phosphate with self-setting ability is expected to enhance its potential application as bone substitute. In this study, mixtures of α-TCP and β-TCP with various compositions were prepared through α-β phase transition of α-TCP powder at 1000 °C for various periods. These powders were mixed with 0.25 M Na{sub 2}HPO{sub 4} at a P/L ratio of 2, and then hardened at 37 °C at 100% RH for up to 24 h. Material properties of biphasic HA/β-TCP cement with different α-TCP/β-TCP composition were characterized. These cements were also evaluated with respect to cell response in vitro using MC3T3-E1 cell lines. In conclusion, mechanical and biological properties of HA/β-TCP cement could be controlled by changing the heat treatment time of α-TCP powder at 1000 °C. In vitro results indicated that cell proliferation and ALP activity increased with increase β-TCP content. - Highlights: • We could fabricate biphasic HA/β-TCP cements using heat treated α-TCP powder. • It is easy to control the ratio of α-TCP to β-TCP changing the heat treatment time up to 48 h. • Both cell number and ALP activity increased with increase in β-TCP content. • In vitro results showed that β-TCP has superior cell affinity to HA.

Occurrence in Mexico, 1998–2008, of Vibrio cholerae CTX+ El Tor carrying an additional truncated CTX prophage

Science.gov (United States)

Alam, Munirul; Rashed, Shah Manzur; Mannan, Shahnewaj Bin; Islam, Tarequl; Lizarraga-Partida, Marcial Leonardo; Delgado, Gabriela; Morales-Espinosa, Rosario; Mendez, Jose Luis; Navarro, Armando; Watanabe, Haruo; Ohnishi, Makoto; Hasan, Nur A.; Huq, Anwar; Sack, R. Bradley; Colwell, Rita R.; Cravioto, Alejandro

2014-01-01

The seventh cholera pandemic caused by Vibrio cholerae O1 El Tor (ET) has been superseded in Asia and Africa by altered ET possessing the cholera toxin (CTX) gene of classical (CL) biotype. The CL biotype of V. cholerae was isolated, along with prototypic and altered ET, during the 1991 cholera epidemic in Mexico and subsequently remained endemic until 1997. Microbiological, molecular, and phylogenetic analyses of clinical and environmental V. cholerae isolated in Mexico between 1998 and 2008 revealed important genetic events favoring predominance of ET over CL and altered ET. V. cholerae altered ET was predominant after 1991 but not after 2000. V. cholerae strains isolated between 2001 and 2003 and a majority isolated in 2004 lacked CTX prophage (Φ) genes encoding CTX subunits A and B and repeat sequence transcriptional regulators of ET and CL biotypes: i.e., CTXΦ−. Most CTXΦ− V. cholerae isolated in Mexico between 2001 and 2003 also lacked toxin coregulated pili tcpA whereas some carried either tcpAET or a variant tcpA with noticeable sequence dissimilarity from tcpACL. The tcpA variants were not detected in 2005 after CTXΦ+ ET became dominant. All clinical and environmental V. cholerae O1 strains isolated during 2005–2008 in Mexico were CTXΦ+ ET, carrying an additional truncated CTXΦ instead of RS1 satellite phage. Despite V. cholerae CTXΦ− ET exhibiting heterogeneity in pulsed-field gel electrophoresis patterns, CTXΦ+ ET isolated during 2004–2008 displayed homogeneity and clonal relationship with V. cholerae ET N16961 and V. cholerae ET isolated in Peru. PMID:24958870

Neutron diffraction and NQR study of the intermediate turn angle phase formed during AFI to AFII recording in YBa2Cu3-xAlxO6+#delta#

DEFF Research Database (Denmark)

Brecht, E.; Schmahl, W.W.; Fuess, H.

1997-01-01

The reordering mechanism from the antiferromagnetic phase AFI to the antiferromagnetic phase AFII in an oxygen-deficient YBa2Cu2.94Al0.06O6+delta single crystal with an oxygen content delta=0.18 in the Cu(1) layer has been studied by neutron diffraction and nuclear quadrupole resonance (NQR......). The crystal orders magnetically from the paramagnetic state to the antiferromagnetic AFI state at the Neel temperature T-N=403 K with an empirical critical exponent of beta = 0.26. Reordering to the antiferromagnetic AFII state sets in at T-2 = 12 K. In both the AFI and AFII phases the ordered magnetic...... as a function of temperature. This result indicates unequivocally that the AFIAFII reordering takes place via a noncollinear intermediate turn angle phase AFI+II....

A Spectral Algorithm for Envelope Reduction of Sparse Matrices

Science.gov (United States)

Barnard, Stephen T.; Pothen, Alex; Simon, Horst D.

1993-01-01

The problem of reordering a sparse symmetric matrix to reduce its envelope size is considered. A new spectral algorithm for computing an envelope-reducing reordering is obtained by associating a Laplacian matrix with the given matrix and then sorting the components of a specified eigenvector of the Laplacian. This Laplacian eigenvector solves a continuous relaxation of a discrete problem related to envelope minimization called the minimum 2-sum problem. The permutation vector computed by the spectral algorithm is a closest permutation vector to the specified Laplacian eigenvector. Numerical results show that the new reordering algorithm usually computes smaller envelope sizes than those obtained from the current standard algorithms such as Gibbs-Poole-Stockmeyer (GPS) or SPARSPAK reverse Cuthill-McKee (RCM), in some cases reducing the envelope by more than a factor of two.

SU-E-T-454: Impact of Calculation Grid Size On Dosimetry and Radiobiological Parameters for Head and Neck IMRT

Energy Technology Data Exchange (ETDEWEB)

Srivastava, S; Das, I [Purdue University, West Lafayette, IN (United States); Indiana University Health Methodist Hospital, Indianapolis, IN (United States); Indiana University- School of Medicine, Indianapolis, IN (United States); Cheng, C [Purdue University, West Lafayette, IN (United States); Indiana University Health Methodist Hospital, Indianapolis, IN (United States)

2014-06-01

Purpose: IMRT has become standard of care for complex treatments to optimize dose to target and spare normal tissues. However, the impact of calculation grid size is not widely known especially dose distribution, tumor control probability (TCP) and normal tissue complication probability (NTCP) which is investigated in this study. Methods: Ten head and neck IMRT patients treated with 6 MV photons were chosen for this study. Using Eclipse TPS, treatment plans were generated for different grid sizes in the range 1–5 mm for the same optimization criterion with specific dose-volume constraints. The dose volume histogram (DVH) was calculated for all IMRT plans and dosimetric data were compared. ICRU-83 dose points such as D2%, D50%, D98%, as well as the homogeneity and conformity indices (HI, CI) were calculated. In addition, TCP and NTCP were calculated from DVH data. Results: The PTV mean dose and TCP decreases with increasing grid size with an average decrease in mean dose by 2% and TCP by 3% respectively. Increasing grid size from 1–5 mm grid size, the average mean dose and NTCP for left parotid was increased by 6.0% and 8.0% respectively. Similar patterns were observed for other OARs such as cochlea, parotids and spinal cord. The HI increases up to 60% and CI decreases on average by 3.5% between 1 and 5 mm grid that resulted in decreased TCP and increased NTCP values. The number of points meeting the gamma criteria of ±3% dose difference and ±3mm DTA was higher with a 1 mm on average (97.2%) than with a 5 mm grid (91.3%). Conclusion: A smaller calculation grid provides superior dosimetry with improved TCP and reduced NTCP values. The effect is more pronounced for smaller OARs. Thus, the smallest possible grid size should be used for accurate dose calculation especially in H and N planning.

INFLUENCIA DE LAS CONDICIONES FISICOQUÍMICAS DEL SEDIMENTO Y LA INTERFASE AGUA-SEDIMENTO EN LA TRANSFERENCIA EXPERIMENTAL DEL O,O-DIETIL O?- 3,5,6 TRICLORO-2-PIRIDINIL FOSFOROTIATO (CLORPIRIFOS Y EL 3,5,6 TRICLORO-2-PIRIDINOL (TCP, EN EL EMBALSE RIOGRANDE II

Directory of Open Access Journals (Sweden)

Diana María Agudelo

2013-12-01

Full Text Available En esta investigación experimental se evaluó la influencia de algunas variables fisicoquímicas de sedimentos procedentes del embalse Riogrande II y de la interfase agua-sedimento en la transferencia de Clorpirifos y TCP. El análisis de clorpirifos y TCP en sedimentos y agua se realizó por extracción en fase sólida. Las muestras fueron detectadas por cromatografía de gases acoplada a espectrometría de masas (Trace GC Ultra MS 2030-Thermo Scientific. Se evidenció una fuerte adsorción de ambos compuestos en los sedimentos, dado el alto contenido de arcillas y de carbono orgánico, lo cual limitó su movilidad hacia la interfase. La interfase agua-sedimento se caracterizó por una condición de hipoxia durante toda la fase experimental, mientras que la conductividad eléctrica aumento en el tiempo. Se determinó que un pH neutro o ligeramente alcalino favoreció el aumento de la concentración de clorpirifos en la interfase agua-sedimento, lo cual sugiere un incremento de su transferencia desde el sedimento a la interfase, mientras que un pH ligeramente ácido favorece la transformación del compuesto parental en el sedimento.

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

Science.gov (United States)

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.

Awareness of pro-tobacco advertising and promotion and beliefs about tobacco use: findings from the Tobacco Control Policy (TCP) India Pilot Survey.

Science.gov (United States)

Bansal-Travers, Maansi; Fong, Geoffrey T; Quah, Anne C K; Sansone, Genevieve; Pednekar, Mangesh S; Gupta, Prakash C; Sinha, Dhirendra N

2014-12-01

Tobacco companies are utilizing similar strategies to advertise and promote their products in developing countries as they have used successfully for over 50 years in developed countries. The present study describes how adult smokers, smokeless tobacco users, and non-users of tobacco from the Tobacco Control Project (TCP) India Pilot Survey, conducted in 2006, responded to questions regarding their perceptions and observations of pro-tobacco advertising and promotion and beliefs about tobacco use. Analyses found that 74% (n=562) of respondents reported seeing some form of pro-tobacco advertising in the last six months, with no differences observed between smokers (74%), smokeless tobacco users (74%), and nonsmokers (73%). More than half of respondents reported seeing pro-tobacco advertising on store windows or inside shops. Overall, this study found that a significant percentage of tobacco users and non-users in India report seeing some form of pro-tobacco advertising and promotion messages. Additional analyses found that smokers were more likely to perceive tobacco use as harmful to their health compared with smokeless tobacco users and non-users (padvertising and promotion of tobacco products in India. Copyright © 2014 Ministry of Health, Saudi Arabia. Published by Elsevier Ltd. All rights reserved.

Awareness of pro-tobacco advertising and promotion and beliefs about tobacco use: Findings from the Tobacco Control Policy (TCP) India Pilot Survey†

Science.gov (United States)

Bansal-Travers, Maansi; Fong, Geoffrey T.; Quah, Anne C.K.; Sansone, Genevieve; Pednekar, Mangesh S.; Gupta, Prakash C.; Sinha, Dhirendra N.

2014-01-01

Tobacco companies are utilizing similar strategies to advertise and promote their products in developing countries as they have used successfully for over 50 years in developed countries. The present study describes how adult smokers, smokeless tobacco users, and non-users of tobacco from the Tobacco Control Project (TCP) India Pilot Survey, conducted in 2006, responded to questions regarding their perceptions and observations of pro-tobacco advertising and promotion and beliefs about tobacco use. Analyses found that 74% (n=562) of respondents reported seeing some form of pro-tobacco advertising in the last six months, with no differences observed between smokers (74%), smokeless tobacco users (74%), and nonsmokers (73%). More than half of respondents reported seeing pro-tobacco advertising on store windows or inside shops. Overall, this study found that a significant percentage of tobacco users and non-users in India report seeing some form of pro-tobacco advertising and promotion messages. Additional analyses found that smokers were more likely to perceive tobacco use as harmful to their health compared with smokeless tobacco users and non-users (padvertising and promotion of tobacco products in India. PMID:25455648

In vitro and in vivo evaluation of a macro porous β-TCP granule-shaped bone substitute fabricated by the fibrous monolithic process

International Nuclear Information System (INIS)

Kim, Young-Hee; Jyoti, M Anirban; Song, Ho-Yeon; Youn, Min-Ho; Lee, Byong-Taek; Youn, Hyung-Sun; Seo, Hyung-Seok

2010-01-01

In this study, a new porous beta-tricalcium phosphate (β-TCP) granule was fabricated using the fibrous monolithic (FM) process and its in vitro biocompatibility and in vivo bone formation were evaluated. SEM micrograph images showed that MG-63 cells attached to the surfaces of the implant and were well proliferated. Cellular viability was as high as 75% in a 50% extract dilution solution. cDNA micro array analysis was also carried out. In this analysis, we found a total of 12 up-regulated and 25 down-regulated genes. Four rabbits were used in the in vivo experiments. 3D micro-CT images showed that the formation of new bone was almost three times greater than that of normal trabecular bone (BV/TV). The histomorphometric results correlated with the micro-CT findings; a greater amount of new bone formation and osteoblast lineage along with osteocytes were observed in the implanted animals. Also x-ray radiographic and 2D micro-CT images were taken to demonstrate the superior biodegradability of the porous granule. As biodegradation occurred along with bone formation, 6 months after implantation, the porous granule structure was not distinguishable separately from that of the trabecular bone.

β-Tricalcium phosphate/poly(glycerol sebacate) scaffolds with robust mechanical property for bone tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Yang, Kai [The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237 (China); Engineering Research Centre for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Zhang, Jing; Ma, Xiaoyu; Ma, Yifan; Kan, Chao [Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Engineering Research Centre for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Ma, Haiyan [Engineering Research Centre for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Li, Yulin, E-mail: yulinli@ecust.edu.cn [Engineering Research Centre for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Yuan, Yuan, E-mail: yyuan@ecust.edu.cn [The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237 (China); Engineering Research Centre for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Liu, Changsheng, E-mail: liucs@ecust.edu.cn [The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237 (China); Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Engineering Research Centre for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China)

2015-11-01

Despite good biocompatibility and osteoconductivity, porous β-TCP scaffolds still lack the structural stability and mechanical robustness, which greatly limit their application in the field of bone regeneration. The hybridization of β-TCP with conventional synthetic biodegradable PLA and PCL only produced a limited toughening effect due to the plasticity of the polymers in nature. In this study, a β-TCP/poly(glycerol sebacate) scaffold (β-TCP/PGS) with well interconnected porous structure and robust mechanical property was prepared. Porous β-TCP scaffold was first prepared with polyurethane sponge as template and then impregnated into PGS pre-polymer solution with moderate viscosity, followed by in situ heat crosslinking and freezing–drying process. The results indicated that the freezing–drying under vacuum process could further facilitate crosslinking of PGS and formation of Ca{sup 2+}–COO{sup −} ionic complexing and thus synergistically improved the mechanical strength of the β-TCP/PGS with in situ heat crosslinking. Particularly, the β-TCP/PGS with 15% PGS content after heat crosslinking at 130 °C and freezing–drying at − 50 °C under vacuum exhibited an elongation at break of 375 ± 25% and a compressive strength of 1.73 MPa, 3.7-fold and 200-fold enhancement compared to the β-TCP, respectively. After the abrupt drop of compressive load, the β-TCP/PGS scaffolds exhibited a full recovery of their original shape. More importantly, the PGS polymer in the β-TCP/PGS scaffolds could direct the biomineralization of Ca/P from particulate shape into a nanofiber-interweaved structure. Furthermore, the β-TCP/PGS scaffolds allowed for cell penetration and proliferation, indicating a good cytobiocompatibility. It is believed that β-TCP/PGS scaffolds have great potential application in rigid tissue regeneration. - Graphical abstract: Robust β-TCP/PGS porous scaffolds are developed by incorporation of poly(glycerol sebacate) (PGS, a flexible

Cloning, characterization and sub-cellular localization of gamma subunit of T-complex protein-1 (chaperonin) from Leishmania donovani

Energy Technology Data Exchange (ETDEWEB)

Bhaskar,; Kumari, Neeti [Division of Biochemistry, CSIR-Central Drug Research Institute, Chattar Manzil Palace, PO Box 173, Lucknow (India); Goyal, Neena, E-mail: neenacdri@yahoo.com [Division of Biochemistry, CSIR-Central Drug Research Institute, Chattar Manzil Palace, PO Box 173, Lucknow (India)

2012-12-07

Highlights: Black-Right-Pointing-Pointer The study presents cloning and characterization of TCP1{gamma} gene from L. donovani. Black-Right-Pointing-Pointer TCP1{gamma} is a subunit of T-complex protein-1 (TCP1), a chaperonin class of protein. Black-Right-Pointing-Pointer LdTCP{gamma} exhibited differential expression in different stages of promastigotes. Black-Right-Pointing-Pointer LdTCP{gamma} co-localized with actin, a cytoskeleton protein. Black-Right-Pointing-Pointer The data suggests that this gene may have a role in differentiation/biogenesis. Black-Right-Pointing-Pointer First report on this chapronin in Leishmania. -- Abstract: T-complex protein-1 (TCP1) complex, a chaperonin class of protein, ubiquitous in all genera of life, is involved in intracellular assembly and folding of various proteins. The gamma subunit of TCP1 complex (TCP1{gamma}), plays a pivotal role in the folding and assembly of cytoskeleton protein(s) as an individual or complexed with other subunits. Here, we report for the first time cloning, characterization and expression of the TCP1{gamma} of Leishmania donovani (LdTCP1{gamma}), the causative agent of Indian Kala-azar. Primary sequence analysis of LdTCP1{gamma} revealed the presence of all the characteristic features of TCP1{gamma}. However, leishmanial TCP1{gamma} represents a distinct kinetoplastid group, clustered in a separate branch of the phylogenic tree. LdTCP1{gamma} exhibited differential expression in different stages of promastigotes. The non-dividing stationary phase promastigotes exhibited 2.5-fold less expression of LdTCP1{gamma} as compared to rapidly dividing log phase parasites. The sub-cellular distribution of LdTCP1{gamma} was studied in log phase promastigotes by employing indirect immunofluorescence microscopy. The protein was present not only in cytoplasm but it was also localized in nucleus, peri-nuclear region, flagella, flagellar pocket and apical region. Co-localization of LdTCP1{gamma} with actin suggests

Neutrino mass ordering and μ-τ reflection symmetry breaking

Science.gov (United States)

Xing, Zhi-zhong; Zhu, Jing-yu

2017-12-01

If the neutrino mass spectrum turns out to be m 3case the columns of the 3×3 lepton flavor mixing matrix U should be reordered accordingly, and the resulting pattern U‧ may involve one or two large mixing angles in the standard parametrization or its variations. Since the Majorana neutrino mass matrix remains unchanged in such a mass relabeling, a possible μ-τ reflection symmetry is respected in this connection and its breaking effects are model-independently constrained at the 3σ level by using current experimental data. Supported by National Natural Science Foundation of China (11135009, 11375207)

18th ICPR paper: Master Production Scheduling and A Comparision of Material Requirements Planning and Cover-Time Planning

OpenAIRE

2006-01-01

Abstract For a company?s long-term profitability, most important processes are the way it starts parts of the manufacturing process before the customer order arrives and the way it determines and promises delivery quantities and times for the customer orders. In practical computer applications Material Requirement Planning and/or Reorder point systems are the base techniques mostly used. This article pre?sents Cover-Time Planning, a variant of a reorder point system. Cover-Time Pla...

Cloning, characterization and sub-cellular localization of gamma subunit of T-complex protein-1 (chaperonin) from Leishmania donovani

International Nuclear Information System (INIS)

Bhaskar,; Kumari, Neeti; Goyal, Neena

2012-01-01

Highlights: ► The study presents cloning and characterization of TCP1γ gene from L. donovani. ► TCP1γ is a subunit of T-complex protein-1 (TCP1), a chaperonin class of protein. ► LdTCPγ exhibited differential expression in different stages of promastigotes. ► LdTCPγ co-localized with actin, a cytoskeleton protein. ► The data suggests that this gene may have a role in differentiation/biogenesis. ► First report on this chapronin in Leishmania. -- Abstract: T-complex protein-1 (TCP1) complex, a chaperonin class of protein, ubiquitous in all genera of life, is involved in intracellular assembly and folding of various proteins. The gamma subunit of TCP1 complex (TCP1γ), plays a pivotal role in the folding and assembly of cytoskeleton protein(s) as an individual or complexed with other subunits. Here, we report for the first time cloning, characterization and expression of the TCP1γ of Leishmania donovani (LdTCP1γ), the causative agent of Indian Kala-azar. Primary sequence analysis of LdTCP1γ revealed the presence of all the characteristic features of TCP1γ. However, leishmanial TCP1γ represents a distinct kinetoplastid group, clustered in a separate branch of the phylogenic tree. LdTCP1γ exhibited differential expression in different stages of promastigotes. The non-dividing stationary phase promastigotes exhibited 2.5-fold less expression of LdTCP1γ as compared to rapidly dividing log phase parasites. The sub-cellular distribution of LdTCP1γ was studied in log phase promastigotes by employing indirect immunofluorescence microscopy. The protein was present not only in cytoplasm but it was also localized in nucleus, peri-nuclear region, flagella, flagellar pocket and apical region. Co-localization of LdTCP1γ with actin suggests that, this gene may have a role in maintaining the structural dynamics of cytoskeleton of parasite.

The effect of boron additions on irradiation-induced order changes in Ni3Al intermetallic compounds

International Nuclear Information System (INIS)

Njah, N.; Gilbon, D.; Dimitrov, O.

1995-01-01

The effects of boron additions (0.1 wt%) on the kinetics of atomic order changes in a Ni 76 Al 24 intermetallic compound, under 1 MeV electron irradiation, were investigated at temperatures of 293 K and 410 K and displacement rates of 0.09 x 10 -3 to 4.7 x 10 -3 dpa.s -1 . In these irradiation conditions, a state of residual order was obtained for long irradiation times, characterized by a steady state order parameter S∞; it corresponds to a competition between two opposite features: irradiation disordering and thermal reordering enhanced by irradiation. Boron additions did not affect the efficiency of irradiation-induced disordering: the disordering cross-section (or, equivalently, the number of replacements per displacement var-epsilon) were comparable with and without a boron addition. By contrast, the S∞ values at 293 K were much lower in the alloy containing boron. Since boron does not change the disordering rate, the large difference between the values obtained in undoped and in boron-doped alloys shows that the reordering rate is strongly reduced by the presence of boron. Thus, boron modifies the mobility of the defects responsible for the irradiation-enhanced diffusion. The data on dislocation-loop size and the reordering kinetics suggest that vacancies are trapped by boron at low temperatures and immobilized, probably by the formation of a boron-vacancy complex. The effect becomes weaker at higher displacement rates and higher temperatures, probably due to the boron-vacancy complexes becoming unstable. It is proposed that two different reordering mechanisms may be operative at 293 K, according to the presence of boron: reordering is promoted by vacancy migration in the Ni 76 Al 24 alloy, whereas in the Ni 76 Al 24 (0.1 wt%B) alloy, it is promoted by the migration of split-interstitials or/and of low-mobility vacancy-boron complexes

The induction of dentin bridge-like structures by constructs of subcultured dental pulp-derived cells and porous HA/TCP in porcine teeth.

Science.gov (United States)

Ando, Yusuke; Honda, Masaki J; Ohshima, Hayato; Tonomura, Akiko; Ohara, Takayuki; Itaya, Toshimitsu; Kagami, Hideaki; Ueda, Minoru

2009-02-01

The purpose of this study was to investigate dentin-bridge formation in teeth following the transplantation of dental pulp-derived cells seeded on hydroxyapatite/tricalcium phosphate (HA/TCP) scaffolds. The dental pulp tissues were removed from the extracted first molar teeth of miniature pigs and single cell populations were subcultured. Second-passage cells that had alkaline phosphatase activity were combined with scaffolds. Cell-scaffold constructs were placed in contact with the exposed pulp tissue. The dimensions of the exposed pulp site were approximately 1-2.5 mm in diameter and 2-3 mm in depth from the tooth surface. After placing the constructs, the tooth was restored with composite resin. Six weeks after transplantation, hard tissue formation was observed on the pulp tissue in histology. Dentinal tubule-like structures were observed in most of the hard tissue generated, and columnar cells, which showed positive immunoreactions with dentin sialoprotein (DSP) and heat shock protein (HSP)-25, were aligned beneath the hard tissues. When only scaffolds were placed on the pulp tissues, particles of hard tissue were formed, however dentinal tubule-like structures and odontoblasts were not observed despite the formation of hard tissue. In conclusion, the implantation of dental pulp constructs into pulp exposed stimulates the formation of calcified dentin-like structures.

Interaction of 2,4,6-trichlorophenol with high carbon iron filings: Reaction and sorption mechanisms

Energy Technology Data Exchange (ETDEWEB)

Sinha, Alok [Environmental Engineering and Management Programme, Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Bose, Purnendu [Environmental Engineering and Management Programme, Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur 208016 (India)], E-mail: pbose@iitk.ac.in

2009-05-15

Reductive dehalogenation of 2,4,6-trichlorophenol (2,4,6-TCP) by two types of high carbon iron filings (HCIF), HCIF-1 and HCIF-2 was studied in batch reactors. While the iron, copper, manganese and carbon content of the two types of HCIF was similar, the specific surface area of HCIF-1 and HCIF-2 were 1.944 and 3.418 m{sup 2} g{sup -1}, respectively. During interaction with HCIF-1, 2,4,6-TCP adsorbed on HCIF-1 surface resulting in rapid reduction of aqueous phase 2,4,6-TCP concentration. However, reductive dehalogenation of 2,4,6-TCP was negligible. During interaction between 2,4,6-TCP and HCIF-2, both 2,4,6-TCP adsorption on HCIF-2, and 2,4,6,-TCP dechlorination was observed. 2,4,6-TCP partitioning between solid and aqueous phase could be described by a Freundlich isotherm, while 2,4,6-TCP dechlorination could be described by an appropriate rate expression. A mathematical model was developed for describing the overall interaction of 2,4,6-TCP with HCIF-2, incorporating simultaneous adsorption/desorption and dechlorination reactions of 2,4,6-TCP with the HCIF surface. 2,4-Dichlorophenol (2,4-DCP), 2-chlorophenol (2-CP) and minor amounts of 4-chlorophenol (4-CP) evolved as 2,4,6-TCP dechlorination by-products. The evolved 2,4-DCP partitioned strongly to the HCIF surface. 4-CP and 2-CP accumulated in the aqueous phase. No transformation of 2-CP or 4-CP to phenol was observed.

Preclinical evaluation of technetium 99m-labeled P1827DS for infection imaging and comparison with technetium 99m IL-8

International Nuclear Information System (INIS)

Krause, Sabine; Rennen, Huub J.; Boerman, Otto C.; Baumann, Sabine; Cyr, John E.; Manchanda, Rajesh; Lister-James, John; Corstens, Frans C.; Dinkelborg, Ludger M.

2007-01-01

Background: The technetium 99 m ( 99m Tc)-radiolabeled, leukocyte-avid peptide-glycoseaminoglycan complex, [ 99m Tc]P1827DS, has been synthesized as an improved infection/inflammation imaging agent to [ 99m Tc]P483H (LeukoTect, Diatide). In a phase I/II clinical trail, [ 99m Tc]P483H images were equivalent to those obtained with 111 In ex vivo labeled leukocytes. However, there was physiologic accumulation of radioactivity in the body that could hamper interpretation of the images. In this study, the potential of [ 99m Tc]P1827DS for infection imaging was assessed in comparison with [ 99m Tc]P483H and the well-described imaging agent [ 99m Tc] hydrazinonicotinamide (HYNIC)-interleukin 8 (IL-8). Methods: The binding of [ 99m Tc]P1827DS to human blood cell was studied in vitro. A rabbit Escherichia coli infection model was used to perform the biodistribution and imaging studies with [ 99m Tc]P1827DS, [ 99m Tc]P483H and [ 99m Tc]HYNIC-IL-8. Results: [ 99m Tc]P1827DS binds to leukocytes but not to erythrocytes. The leukocyte binding was not saturable up to an investigated concentration of 10 μM. The accumulation of [ 99m Tc]P1827/DS at the infection site strongly depends on the P1827/DS ratio and was optimal at a molar ratio of 10:1. [ 99m Tc]P1827DS shows improved biodistribution over [ 99m Tc]P483H with similar uptake at the infection site. Abscess uptake of [ 99m Tc]HYNIC-IL-8 was approximately three times higher than that of [ 99m Tc]P1827DS. [ 99m Tc]HYNIC-IL-8 showed high accumulation in the kidneys, whereas [ 99m Tc]P1827DS showed high lung uptake and slightly higher accumulation in the liver and spleen. Conclusion: [ 99m Tc]P1827DS is a potential new inflammation imaging agent, which clearly visualized the abscess in the rabbit E. coli infection model and showed improved biodistribution compared to [ 99m Tc]P483H. However, the infection uptake and biodistribution of [ 99m Tc]P1827DS is not superior to that of [ 99m Tc]HYNIC-IL-8 in this animal model

Progressive retry for software error recovery in distributed systems

Science.gov (United States)

Wang, Yi-Min; Huang, Yennun; Fuchs, W. K.

1993-01-01

In this paper, we describe a method of execution retry for bypassing software errors based on checkpointing, rollback, message reordering and replaying. We demonstrate how rollback techniques, previously developed for transient hardware failure recovery, can also be used to recover from software faults by exploiting message reordering to bypass software errors. Our approach intentionally increases the degree of nondeterminism and the scope of rollback when a previous retry fails. Examples from our experience with telecommunications software systems illustrate the benefits of the scheme.

iRaster: a novel information visualization tool to explore spatiotemporal patterns in multiple spike trains.

Science.gov (United States)

Somerville, J; Stuart, L; Sernagor, E; Borisyuk, R

2010-12-15

Over the last few years, simultaneous recordings of multiple spike trains have become widely used by neuroscientists. Therefore, it is important to develop new tools for analysing multiple spike trains in order to gain new insight into the function of neural systems. This paper describes how techniques from the field of visual analytics can be used to reveal specific patterns of neural activity. An interactive raster plot called iRaster has been developed. This software incorporates a selection of statistical procedures for visualization and flexible manipulations with multiple spike trains. For example, there are several procedures for the re-ordering of spike trains which can be used to unmask activity propagation, spiking synchronization, and many other important features of multiple spike train activity. Additionally, iRaster includes a rate representation of neural activity, a combined representation of rate and spikes, spike train removal and time interval removal. Furthermore, it provides multiple coordinated views, time and spike train zooming windows, a fisheye lens distortion, and dissemination facilities. iRaster is a user friendly, interactive, flexible tool which supports a broad range of visual representations. This tool has been successfully used to analyse both synthetic and experimentally recorded datasets. In this paper, the main features of iRaster are described and its performance and effectiveness are demonstrated using various types of data including experimental multi-electrode array recordings from the ganglion cell layer in mouse retina. iRaster is part of an ongoing research project called VISA (Visualization of Inter-Spike Associations) at the Visualization Lab in the University of Plymouth. The overall aim of the VISA project is to provide neuroscientists with the ability to freely explore and analyse their data. The software is freely available from the Visualization Lab website (see www.plymouth.ac.uk/infovis). Copyright © 2010

WE-AB-207B-11: Optimizing Tumor Control Probability in Radiation Therapy Treatment - Application to HDR Cervical Cancer

Energy Technology Data Exchange (ETDEWEB)

Lee, E [Georgia Institute of Technology, Atlanta, GA (Georgia); Yuan, F [Georgia Institute of Technology, Atlanta, GEORGIA (United States); Templeton, A [Rush University Medical Center, Chicago, IL (United States); Yao, R [Columbus Regional Healthcare, Columbus, GA (United States); Chu, J [Rush University Medical Center, Oak Brook, IL (United States)

2016-06-15

Purpose: The ultimate goal of radiotherapy treatment planning is to find a treatment that will yield a high tumor-control-probability(TCP) with an acceptable normal-tissue-complication probability(NTCP). Yet most treatment planning today is not based upon optimization of TCPs and NTCPs, but rather upon meeting physical dose and volume constraints defined by the planner. We design treatment plans that optimize TCP directly and contrast them with the clinical dose-based plans. PET image is incorporated to evaluate gain in TCP for dose escalation. Methods: We build a nonlinear mixed integer programming optimization model that maximizes TCP directly while satisfying the dose requirements on the targeted organ and healthy tissues. The solution strategy first fits the TCP function with a piecewise-linear approximation, then solves the problem that maximizes the piecewise linear approximation of TCP, and finally performs a local neighborhood search to improve the TCP value. To gauge the feasibility, characteristics, and potential benefit of PET-image guided dose escalation, initial validation consists of fifteen cervical cancer HDR patient cases. These patients have all received prior 45Gy of external radiation dose. For both escalated strategies, we consider 35Gy PTV-dose, and two variations (37Gy-boost to BTV vs 40Gy-boost) to PET-image-pockets. Results: TCP for standard clinical plans range from 59.4% - 63.6%. TCP for dose-based PET-guided escalated-dose-plan ranges from 63.8%–98.6% for all patients; whereas TCP-optimized plans achieves over 91% for all patients. There is marginal difference in TCP among those with 37Gy-boosted vs 40Gy-boosted. There is no increase in rectum and bladder dose among all plans. Conclusion: Optimizing TCP directly results in highly conformed treatment plans. The TCP-optimized plan is individualized based on the biological PET-image of the patients. The TCP-optimization framework is generalizable and has been applied successfully to other

WE-AB-207B-11: Optimizing Tumor Control Probability in Radiation Therapy Treatment - Application to HDR Cervical Cancer

International Nuclear Information System (INIS)

Lee, E; Yuan, F; Templeton, A; Yao, R; Chu, J

2016-01-01

Purpose: The ultimate goal of radiotherapy treatment planning is to find a treatment that will yield a high tumor-control-probability(TCP) with an acceptable normal-tissue-complication probability(NTCP). Yet most treatment planning today is not based upon optimization of TCPs and NTCPs, but rather upon meeting physical dose and volume constraints defined by the planner. We design treatment plans that optimize TCP directly and contrast them with the clinical dose-based plans. PET image is incorporated to evaluate gain in TCP for dose escalation. Methods: We build a nonlinear mixed integer programming optimization model that maximizes TCP directly while satisfying the dose requirements on the targeted organ and healthy tissues. The solution strategy first fits the TCP function with a piecewise-linear approximation, then solves the problem that maximizes the piecewise linear approximation of TCP, and finally performs a local neighborhood search to improve the TCP value. To gauge the feasibility, characteristics, and potential benefit of PET-image guided dose escalation, initial validation consists of fifteen cervical cancer HDR patient cases. These patients have all received prior 45Gy of external radiation dose. For both escalated strategies, we consider 35Gy PTV-dose, and two variations (37Gy-boost to BTV vs 40Gy-boost) to PET-image-pockets. Results: TCP for standard clinical plans range from 59.4% - 63.6%. TCP for dose-based PET-guided escalated-dose-plan ranges from 63.8%–98.6% for all patients; whereas TCP-optimized plans achieves over 91% for all patients. There is marginal difference in TCP among those with 37Gy-boosted vs 40Gy-boosted. There is no increase in rectum and bladder dose among all plans. Conclusion: Optimizing TCP directly results in highly conformed treatment plans. The TCP-optimized plan is individualized based on the biological PET-image of the patients. The TCP-optimization framework is generalizable and has been applied successfully to other

A Novel Method for Surface Defect Detection of Photovoltaic Module Based on Independent Component Analysis

Directory of Open Access Journals (Sweden)

Xuewu Zhang

2013-01-01

Full Text Available This paper proposed a new method for surface defect detection of photovoltaic module based on independent component analysis (ICA reconstruction algorithm. Firstly, a faultless image is used as the training image. The demixing matrix and corresponding ICs are obtained by applying the ICA in the training image. Then we reorder the ICs according to the range values and reform the de-mixing matrix. Then the reformed de-mixing matrix is used to reconstruct the defect image. The resulting image can remove the background structures and enhance the local anomalies. Experimental results have shown that the proposed method can effectively detect the presence of defects in periodically patterned surfaces.

Clustering by reordering of similarity and Laplacian matrices: Application to galaxy clusters

Science.gov (United States)

Mahmoud, E.; Shoukry, A.; Takey, A.

2018-04-01

Similarity metrics, kernels and similarity-based algorithms have gained much attention due to their increasing applications in information retrieval, data mining, pattern recognition and machine learning. Similarity Graphs are often adopted as the underlying representation of similarity matrices and are at the origin of known clustering algorithms such as spectral clustering. Similarity matrices offer the advantage of working in object-object (two-dimensional) space where visualization of clusters similarities is available instead of object-features (multi-dimensional) space. In this paper, sparse ɛ-similarity graphs are constructed and decomposed into strong components using appropriate methods such as Dulmage-Mendelsohn permutation (DMperm) and/or Reverse Cuthill-McKee (RCM) algorithms. The obtained strong components correspond to groups (clusters) in the input (feature) space. Parameter ɛi is estimated locally, at each data point i from a corresponding narrow range of the number of nearest neighbors. Although more advanced clustering techniques are available, our method has the advantages of simplicity, better complexity and direct visualization of the clusters similarities in a two-dimensional space. Also, no prior information about the number of clusters is needed. We conducted our experiments on two and three dimensional, low and high-sized synthetic datasets as well as on an astronomical real-dataset. The results are verified graphically and analyzed using gap statistics over a range of neighbors to verify the robustness of the algorithm and the stability of the results. Combining the proposed algorithm with gap statistics provides a promising tool for solving clustering problems. An astronomical application is conducted for confirming the existence of 45 galaxy clusters around the X-ray positions of galaxy clusters in the redshift range [0.1..0.8]. We re-estimate the photometric redshifts of the identified galaxy clusters and obtain acceptable values

Successful therapy with hemoperfusion and plasma exchange in acute 1,2,3-trichloropropane poisoning.

Science.gov (United States)

Liu, P; Liang, Y-G; Meng, Q-Y; Zhang, C-G; Wang, H-C; Zhang, X-G; Li, G; Liu, Z-Y; He, Y-Z

2012-05-01

1,2,3-trichloropropane (1,2,3-TCP) is commonly used as an intermediate in pesticide and an industrial specialty solvent. Acute 1,2,3-TCP poisoning is rare but a medical emergency. Sporadic cases of toxic hepatic injury from 1,2,3-TCP in humans have been reported. Liver is a target organ for 1,2,3-TCP toxicity, which may ensue in a short period after ingestion. A specific antidote against 1,2,3-TCP is not available. So it is important to distinguish that a patient with 1,2,3-TCP poisoning constitutes a medical emergency. In this case study, the poisoned patient's clinical condition and laboratory values improved gradually after she received hemoperfusion (HP) and plasma exchange, which indicated that the therapy with HP and plasma exchange were helpful in the treatment of 1,2,3-TCP poisoning.

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.

Science.gov (United States)

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.

β-Tricalcium phosphate/poly(glycerol sebacate) scaffolds with robust mechanical property for bone tissue engineering.

Science.gov (United States)

Yang, Kai; Zhang, Jing; Ma, Xiaoyu; Ma, Yifan; Kan, Chao; Ma, Haiyan; Li, Yulin; Yuan, Yuan; Liu, Changsheng

2015-11-01

Despite good biocompatibility and osteoconductivity, porous β-TCP scaffolds still lack the structural stability and mechanical robustness, which greatly limit their application in the field of bone regeneration. The hybridization of β-TCP with conventional synthetic biodegradable PLA and PCL only produced a limited toughening effect due to the plasticity of the polymers in nature. In this study, a β-TCP/poly(glycerol sebacate) scaffold (β-TCP/PGS) with well interconnected porous structure and robust mechanical property was prepared. Porous β-TCP scaffold was first prepared with polyurethane sponge as template and then impregnated into PGS pre-polymer solution with moderate viscosity, followed by in situ heat crosslinking and freezing-drying process. The results indicated that the freezing-drying under vacuum process could further facilitate crosslinking of PGS and formation of Ca(2+)-COO(-) ionic complexing and thus synergistically improved the mechanical strength of the β-TCP/PGS with in situ heat crosslinking. Particularly, the β-TCP/PGS with 15% PGS content after heat crosslinking at 130°C and freezing-drying at -50°C under vacuum exhibited an elongation at break of 375±25% and a compressive strength of 1.73MPa, 3.7-fold and 200-fold enhancement compared to the β-TCP, respectively. After the abrupt drop of compressive load, the β-TCP/PGS scaffolds exhibited a full recovery of their original shape. More importantly, the PGS polymer in the β-TCP/PGS scaffolds could direct the biomineralization of Ca/P from particulate shape into a nanofiber-interweaved structure. Furthermore, the β-TCP/PGS scaffolds allowed for cell penetration and proliferation, indicating a good cytobiocompatibility. It is believed that β-TCP/PGS scaffolds have great potential application in rigid tissue regeneration. Copyright © 2015 Elsevier B.V. All rights reserved.

The role of the chemical composition of monetite on the synthesis and properties of α-tricalcium phosphate

Energy Technology Data Exchange (ETDEWEB)

Duncan, Jo, E-mail: jo.duncan@abdn.ac.uk [Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE (United Kingdom); MacDonald, James F., E-mail: J.F.MacDonald@warwick.ac.uk [Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL (United Kingdom); Hanna, John V., E-mail: J.V.Hanna@warwick.ac.uk [Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL (United Kingdom); Shirosaki, Yuki, E-mail: yukis@cc.okayama-u.ac.jp [Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima, Kita-ku, Okayama 700-8530 (Japan); Hayakawa, Satoshi, E-mail: satoshi@cc.okayama-u.ac.jp [Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima, Kita-ku, Okayama 700-8530 (Japan); Osaka, Akiyoshi, E-mail: a-osaka@cc.okayama-u.ac.jp [Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima, Kita-ku, Okayama 700-8530 (Japan); Skakle, Janet M.S., E-mail: j.skakle@abdn.ac.uk [Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE (United Kingdom); Gibson, Iain R., E-mail: i.r.gibson@abdn.ac.uk [Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE (United Kingdom); School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD (United Kingdom)

2014-01-01

There has been a resurgence of interest in alpha-tricalcium phosphate (α-TCP), with use in cements, polymer composites and in bi- and tri-phasic calcium phosphate bone grafts. The simplest and most established method for preparing α-TCP is the solid state reaction of monetite (CaHPO{sub 4}) and calcium carbonate at high temperatures, followed by quenching. In this study, the effect of the chemical composition of reagents used in the synthesis of α-TCP on the local structure of the final product is reported and findings previously reported pertaining to the phase composition and stability are also corroborated. Chemical impurities in the monetite reagents were identified and could be correlated to the calcium phosphate products formed; magnesium impurities favoured the formation of β-TCP, whereas single phase α-TCP was favoured when magnesium levels were low. Monetite synthesised in-house exhibited a high level of chemical purity; when this source was used to produce an α-TCP sample, the α-polymorph could be obtained by both quenching and by cooling to room temperature in the furnace at rates between 1 and 10 °C/min, thereby simplifying the synthesis process. It was only when impurities were minimised that the 12 phosphorus environments in the α-TCP structure could be resolved by {sup 31}P nuclear magnetic resonance; samples containing chemical impurity showed differing degrees of line-broadening. Reagent purity should therefore be considered a priority when synthesising/characterising the α-polymorph of TCP. - Highlights: • Most commercial sources of monetite contain impurities that affect synthesis of phase pure α-TCP. • Ratio of α:β-TCP polymorphs formed by solid state reaction is dependent on reactant chemical purity. • If reagents in α-TCP synthesis are chemically pure, quenching is not required to obtain α-polymorph. • 12 unique P sites in α-TCP were only fully realised by {sup 31}P NMR when chemically pure reagents are used. �

Treatment of osteomyelitis defects by a vancomycin-loaded gelatin/β-tricalcium phosphate composite scaffold

Science.gov (United States)

Zhou, J.; Zhou, X. G.; Wang, J. W.; Zhou, H.; Dong, J.

2018-01-01

Objective In the present study, we aimed to assess whether gelatin/β-tricalcium phosphate (β-TCP) composite porous scaffolds could be used as a local controlled release system for vancomycin. We also investigated the efficiency of the scaffolds in eliminating infections and repairing osteomyelitis defects in rabbits. Methods The gelatin scaffolds containing differing amounts of of β-TCP (0%, 10%, 30% and 50%) were prepared for controlled release of vancomycin and were labelled G-TCP0, G-TCP1, G-TCP3 and G-TCP5, respectively. The Kirby-Bauer method was used to examine the release profile. Chronic osteomyelitis models of rabbits were established. After thorough debridement, the osteomyelitis defects were implanted with the scaffolds. Radiographs and histological examinations were carried out to investigate the efficiency of eliminating infections and repairing bone defects. Results The prepared gelatin/β-TCP scaffolds exhibited a homogeneously interconnected 3D porous structure. The G-TCP0 scaffold exhibited the longest duration of vancomycin release with a release duration of eight weeks. With the increase of β-TCP contents, the release duration of the β-TCP-containing composite scaffolds was decreased. The complete release of vancomycin from the G-TCP5 scaffold was achieved within three weeks. In the treatment of osteomyelitis defects in rabbits, the G-TCP3 scaffold showed the most efficacious performance in eliminating infections and repairing bone defects. Conclusions The composite scaffolds could achieve local therapeutic drug levels over an extended duration. The G-TCP3 scaffold possessed the optimal porosity, interconnection and controlled release performance. Therefore, this scaffold could potentially be used in the treatment of chronic osteomyelitis defects. Cite this article: J. Zhou, X. G. Zhou, J. W. Wang, H. Zhou, J. Dong. Treatment of osteomyelitis defects by a vancomycin-loaded gelatin/β-tricalcium phosphate composite scaffold. Bone Joint Res

Combinatorial metabolic engineering of Pseudomonas putida KT2440 for efficient mineralization of 1,2,3-trichloropropane.

Science.gov (United States)

Gong, Ting; Xu, Xiaoqing; Che, You; Liu, Ruihua; Gao, Weixia; Zhao, Fengjie; Yu, Huilei; Liang, Jingnan; Xu, Ping; Song, Cunjiang; Yang, Chao

2017-08-01

An industrial waste, 1,2,3-trichloropropane (TCP), is toxic and extremely recalcitrant to biodegradation. To date, no natural TCP degraders able to mineralize TCP aerobically have been isolated. In this work, we engineered a biosafety Pseudomonas putida strain KT2440 for aerobic mineralization of TCP by implantation of a synthetic biodegradation pathway into the chromosome and further improved TCP mineralization using combinatorial engineering strategies. Initially, a synthetic pathway composed of haloalkane dehalogenase, haloalcohol dehalogenase and epoxide hydrolase was functionally assembled for the conversion of TCP into glycerol in P. putida KT2440. Then, the growth lag-phase of using glycerol as a growth precursor was eliminated by deleting the glpR gene, significantly enhancing the flux of carbon through the pathway. Subsequently, we improved the oxygen sequestering capacity of this strain through the heterologous expression of Vitreoscilla hemoglobin, which makes this strain able to mineralize TCP under oxygen-limited conditions. Lastly, we further improved intracellular energy charge (ATP/ADP ratio) and reducing power (NADPH/NADP + ratio) by deleting flagella-related genes in the genome of P. putida KT2440. The resulting strain (named KTU-TGVF) could efficiently utilize TCP as the sole source of carbon for growth. Degradation studies in a bioreactor highlight the value of this engineered strain for TCP bioremediation.

Radiation synthesis of gelatin/CM-chitosan/{beta}-tricalcium phosphate composite scaffold for bone tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Zhou Ying [College of Engineering, Peking University, Beijing 100871 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Xu Ling, E-mail: lingxu@pku.edu.cn [College of Engineering, Peking University, Beijing 100871 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zhang Xiangmei; Zhao Yinghui [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Wei Shicheng, E-mail: sc-wei@pku.edu.cn [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Peking University, Beijing 100081 (China); Zhai Maolin [Beijing National Laboratory for Molecular Sciences, Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)

2012-05-01

A series of biodegradable composite scaffolds was fabricated from an aqueous solution of gelatin, carboxymethyl chitosan (CM-chitosan) and {beta}-tricalcium phosphate ({beta}-TCP) by radiation-induced crosslinking at ambient temperature. Ultrasonic treatment on the polymer solutions significantly influenced the distribution of {beta}-TCP particles. An ultrasonic time of 20 min, followed by 30 kGy irradiation induced a crosslinked scaffold with homogeneous distribution of {beta}-TCP particles, interconnected porous structure, sound swelling capacity and mechanical strength. Fourier Transform Infrared Spectroscopy and X-ray Diffraction analysis indicated that {beta}-TCP successfully incorporated with the network of gelatin and CM-chitosan. In vivo implantation of the scaffold into the mandible of beagle dog revealed that the scaffolds had excellent biocompatibility and the presence of {beta}-TCP can accelerate bone regeneration. The comprehensive results of this study paved way for the application of gelatin/CM-chitosan/{beta}-TCP composite scaffolds as candidate of bone tissue engineering material. - Highlights: Black-Right-Pointing-Pointer Radiation induced a crosslinked scaffold with interconnected porous structure. Black-Right-Pointing-Pointer Ultrasonic time of 20 min led to homogenerously distribution of {beta}-TCP. Black-Right-Pointing-Pointer Increasing amount of {beta}-TCP would restrict the swelling properties. Black-Right-Pointing-Pointer Proper fraction of {beta}-TCP will promote the mechanical properties of the scaffolds. Black-Right-Pointing-Pointer Hybrid of {beta}-TCP promoted the bone regeneration of the mandibles of beagle dogs.

Bone regeneration by means of a three-dimensional printed scaffold in a rat cranial defect.

Science.gov (United States)

Kwon, Doo Yeon; Park, Ji Hoon; Jang, So Hee; Park, Joon Yeong; Jang, Ju Woong; Min, Byoung Hyun; Kim, Wan-Doo; Lee, Hai Bang; Lee, Junhee; Kim, Moon Suk

2018-02-01

Recently, computer-designed three-dimensional (3D) printing techniques have emerged as an active research area with almost unlimited possibilities. In this study, we used a computer-designed 3D scaffold to drive new bone formation in a bone defect. Poly-L-lactide (PLLA) and bioactive β-tricalcium phosphate (TCP) were simply mixed to prepare ink. PLLA + TCP showed good printability from the micronozzle and solidification within few seconds, indicating that it was indeed printable ink for layer-by-layer printing. In the images, TCP on the surface of (and/or inside) PLLA in the printed PLLA + TCP scaffold looked dispersed. MG-63 cells (human osteoblastoma) adhered to and proliferated well on the printed PLLA + TCP scaffold. To assess new bone formation in vivo, the printed PLLA + TCP scaffold was implanted into a full-thickness cranial bone defect in rats. The new bone formation was monitored by microcomputed tomography and histological analysis of the in vivo PLLA + TCP scaffold with or without MG-63 cells. The bone defect was gradually spontaneously replaced with new bone tissues when we used both bioactive TCP and MG-63 cells in the PLLA scaffold. Bone formation driven by the PLLA + TCP30 scaffold with MG-63 cells was significantly greater than that in other experimental groups. Furthermore, the PLLA + TCP scaffold gradually degraded and matched well the extent of the gradual new bone formation on microcomputed tomography. In conclusion, the printed PLLA + TCP scaffold effectively supports new bone formation in a cranial bone defect. Copyright © 2017 John Wiley & Sons, Ltd.

Global Journal of Engineering Science and Researches

OpenAIRE

Prof. Rama Prabha K P; Prof. Jayanthi R

2016-01-01

Inside wireless LAN, access point always sends long term TCP packets first followed by short term TCP packets. Due to this, there is unfairness for short term packets. In this paper, we come up with a novel approach to address this issue using a priority based scheme and URG (urgent) flag in TCP header. At the same time round robin mechanism is used for non-priority based short term TCP packets which not only improves throughput of the network and provides fairness but also avoids TCP from im...

Entropic stabilisation of topologically close-packed phases in binary transition-metal alloys

Energy Technology Data Exchange (ETDEWEB)

Hammerschmidt, Thomas; Fries, Suzana G.; Steinbach, Ingo; Drautz, Ralf [ICAMS, Ruhr-Universitaet Bochum, Bochum (Germany); Seiser, Bernhard; Pettifor, David G. [Department of Materials, University of Oxford, Oxford (United Kingdom)

2010-07-01

The formation of topologically close-packed (tcp) phases in Ni-based superalloys leads to the degradation of the mechanical properties of the alloys. The precipitation of the tcp phases is attributed to refractory elements that are added in low concentration to improve creep resistance. It is well known that the structural stability of the tcp phases A15, {sigma} and {chi} is driven by the average d-band filling. For a direct comparison to experimental phase diagrams, we carried out extensive density-functional theory (DFT) calculations of the tcp phases A15, C14, C15, C36, {mu}, {sigma}, and {chi} in tcp-forming binary transition-metal (TM) systems. We observe several systems such as W-Re with positive values of the heat of formation for all tcp phases although some of the phases are observed experimentally. By combining our DFT total energies with the CALPHAD methodology, we can demonstrate that configurational entropy can stabilise the tcp phases in these systems.

Adsorption isotherms, kinetics, thermodynamics and desorption studies of 2,4,6-trichlorophenol on oil palm empty fruit bunch-based activated carbon

International Nuclear Information System (INIS)

Tan, I.A.W.; Ahmad, A.L.; Hameed, B.H.

2009-01-01

The adsorption characteristics of 2,4,6-trichlorophenol (TCP) on activated carbon prepared from oil palm empty fruit bunch (EFB) were evaluated. The effects of TCP initial concentration, agitation time, solution pH and temperature on TCP adsorption were investigated. TCP adsorption uptake was found to increase with increase in initial concentration, agitation time and solution temperature whereas adsorption of TCP was more favourable at acidic pH. The adsorption equilibrium data were best represented by the Freundlich and Redlich-Peterson isotherms. The adsorption kinetics was found to follow the pseudo-second-order kinetic model. The mechanism of the adsorption process was determined from the intraparticle diffusion model. Boyd plot revealed that the adsorption of TCP on the activated carbon was mainly governed by particle diffusion. Thermodynamic parameters such as standard enthalpy (ΔH o ), standard entropy (ΔS o ), standard free energy (ΔG o ) and activation energy were determined. The regeneration efficiency of the spent activated carbon was high, with TCP desorption of 99.6%.

Mapping ground surface deformation using temporarily coherent point SAR interferometry: Application to Los Angeles Basin

Science.gov (United States)

Zhang, L.; Lu, Zhong; Ding, X.; Jung, H.-S.; Feng, G.; Lee, C.-W.

2012-01-01

Multi-temporal interferometric synthetic aperture radar (InSAR) is an effective tool to detect long-term seismotectonic motions by reducing the atmospheric artifacts, thereby providing more precise deformation signal. The commonly used approaches such as persistent scatterer InSAR (PSInSAR) and small baseline subset (SBAS) algorithms need to resolve the phase ambiguities in interferogram stacks either by searching a predefined solution space or by sparse phase unwrapping methods; however the efficiency and the success of phase unwrapping cannot be guaranteed. We present here an alternative approach – temporarily coherent point (TCP) InSAR (TCPInSAR) – to estimate the long term deformation rate without the need of phase unwrapping. The proposed approach has a series of innovations including TCP identification, TCP network and TCP least squares estimator. We apply the proposed method to the Los Angeles Basin in southern California where structurally active faults are believed capable of generating damaging earthquakes. The analysis is based on 55 interferograms from 32 ERS-1/2 images acquired during Oct. 1995 and Dec. 2000. To evaluate the performance of TCPInSAR on a small set of observations, a test with half of interferometric pairs is also performed. The retrieved TCPInSAR measurements have been validated by a comparison with GPS observations from Southern California Integrated GPS Network. Our result presents a similar deformation pattern as shown in past InSAR studies but with a smaller average standard deviation (4.6 mm) compared with GPS observations, indicating that TCPInSAR is a promising alternative for efficiently mapping ground deformation even from a relatively smaller set of interferograms.

Contributions of an adiabatic initial inversion pulse and K-space Re-ordered by inversion-time at each slice position (KRISP) to control of CSF artifacts and visualization of the brain in FLAIR magnetic resonance imaging

International Nuclear Information System (INIS)

Curati, Walter L.; Oatridge, Angela; Herlihy, Amy H.; Hajnal, Joseph V.; Puri, Basant K.; Bydder, Graeme M.

2001-01-01

AIM: The aim of this study was to compare the performance of three fluid attenuated inversion recovery (FLAIR) pulse sequences for control of cerebrospinal fluid (CSF) and blood flow artifacts in imaging of the brain. The first of these sequences had an initial sinc inversion pulse which was followed by conventional k-space mapping. The second had an initial sinc inversion pulse followed by k-space re-ordered by inversion time at each slice position (KRISP) and the third had an adiabatic initial inversion pulse followed by KRISP. MATERIALS AND METHODS: Ten patients with established disease were studied with all three pulse sequences. Seven were also studied with the adiabatic KRISP sequence after contrast enhancement. Their images were evaluated for patient motion artifact, CSF and blood flow artifact as well as conspicuity of the cortex, meninges, ventricular system, brainstem and cerebellum. The conspicuity of lesions and the degree of enhancement were also evaluated. RESULTS: Both the sinc and adiabatic KRISP FLAIR sequences showed better control of CSF and blood flow artifacts than the conventional FLAIR sequence. In addition the adiabatic KRISP FLAIR sequence showed better control of CSF artifact at the inferior aspect of the posterior fossa. The lesion conspicuity was similar for each of the FLAIR sequences as was the degree of contrast enhancement to that shown with a T 1 weighted spin echo sequence. CONCLUSION: The KRISP FLAIR sequence controls high signal artifacts from CSF flow and blood flow and the adiabatic pulse controls high signal artifacts due to inadequate inversion of the CSF magnetization at the periphery of the head transmitter coil. The KRISP FLAIR sequence also improves cortical and meningeal definition as a result of an edge enhancement effect. The effects are synergistic and can be usefully combined in a single pulse sequence. Curati, W.L. et al. (2001)

Adaptive Radiotherapy for Locally Advanced Non–Small-Cell Lung Cancer Does Not Underdose the Microscopic Disease and has the Potential to Increase Tumor Control

International Nuclear Information System (INIS)

Guckenberger, Matthias; Richter, Anne; Wilbert, Juergen; Flentje, Michael; Partridge, Mike

2011-01-01

Purpose: To evaluate doses to the microscopic disease (MD) in adaptive radiotherapy (ART) for locally advanced non–small-cell lung cancer (NSCLC) and to model tumor control probability (TCP). Methods and Materials: In a retrospective planning study, three-dimensional conformal treatment plans for 13 patients with locally advanced NSCLC were adapted to shape and volume changes of the gross tumor volume (GTV) once or twice during conventionally fractionated radiotherapy with total doses of 66 Gy; doses in the ART plans were escalated using an iso-mean lung dose (MLD) approach compared to non-adapted treatment. Dose distributions to the volumes of suspect MD were simulated for a scenario with synchronous shrinkage of the MD and GTV and for a scenario of a stationary MD despite GTV shrinkage; simulations were performed using deformable image registration. TCP calculations considering doses to the GTV and MD were performed using three different models. Results: Coverage of the MD at 50 Gy was not compromised by ART. Coverage at 60 Gy in the scenario of a stationary MD was significantly reduced from 92% ± 10% to 73% ± 19% using ART; however, the coverage was restored by iso-MLD dose escalation. Dose distributions in the MD were sufficient to achieve a TCP >80% on average in all simulation experiments, with the clonogenic cell density the major factor influencing TCP. The combined TCP for the GTV and MD was 19.9% averaged over all patients and TCP models in non-adaptive treatment with 66 Gy. Iso-MLD dose escalation achieved by ART increased the overall TCP by absolute 6% (adapting plan once) and by 8.7% (adapting plan twice) on average. Absolute TCP values were significantly different between the TCP models; however, all TCP models suggested very similar TCP increase by using ART. Conclusions: Adaptation of radiotherapy to the shrinking GTV did not compromise dose coverage of volumes of suspect microscopic disease and has the potential to increase TCP by >40% compared

Synthesis and characterizations of alginate-α-tricalcium phosphate microparticle hybrid film with flexibility and high mechanical property as a biomaterial.

Science.gov (United States)

Das, Dipankar; Zhang, Shengmin; Noh, Insup

2018-01-24

A biocompatible hybrid film has been fabricated using alginate (Alg), α-tricalcium phosphate (α-TCP) microparticle and calcium chloride through ionic crosslinking as a biomaterial. The 'screeding method' (like a concrete finishing process) has been employed to develop the Alg-α-TCP film. For this method, the Alg/α-TCP blend has been prepared using an ultra-sonicator and then put on a glass slide. After that, the excess volume of blend has been cut off by skidding another slide along with the surface of the blend to achieve proper grade and flatness. The mechanical strength and flexibility of the film (Alg-α-TCP) has been controlled by changing its compositions. The crosslinking phenomenon has been confirmed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), 13 C nuclear magnetic resonance (NMR), x-ray diffraction and thermogravimetric analyses. The ATR-FTIR and 13 C NMR analysis results suggest that carboxylate groups of the alginate are ionically cross-linked with Ca 2+ ions, while the α-TCP particles reside in the network by physical interaction. The micro-fatigue test results imply high tensile strength (up to 257 MPa) and flexibility (up to 13% elongation) of the Alg-α-TCP hybrid films. The SEM analysis suggests the α-TCP particles are homogeneously distributed on the surface of Alg-α-TCP films, whereas cross-sectional images confirmed the presence of α-TCP in the cross-linked network. TGA results demonstrated that thermal stability of the hybrid film was enhanced due to ionic crosslinking and interfacial interaction between alginate and α-TCP. The incorporation of α-TCP particles diminished the swelling ratio of the hybrid film. The in vitro bone cell (MC3T3) culture and cytotoxicity tests showed that the hybrid film is biocompatible. The hybrid film releases bovine serum albumin and dimethyloxaloylglycine in a controlled way at pH 7 and 7.4, and 37 °C. Overall, the biocompatible Alg-α-TCP hybrid film with

Effect of a Particulate and a Putty-Like Tricalcium Phosphate-Based Bone-grafting Material on Bone Formation, Volume Stability and Osteogenic Marker Expression after Bilateral Sinus Floor Augmentation in Humans

Directory of Open Access Journals (Sweden)

Christine Knabe

2017-07-01

Full Text Available This study examines the effect of a hyaluronic acid (HyAc containing tricalcium phosphate putty scaffold material (TCP-P and of a particulate tricalcium phosphate (TCP-G graft on bone formation, volume stability and osteogenic marker expression in biopsies sampled 6 months after bilateral sinus floor augmentation (SFA in 7 patients applying a split-mouth design. 10% autogenous bone chips were added to the grafting material during surgery. The grain size of the TCP granules was 700 to 1400 µm for TCP-G and 125 to 250 µm and 500 to 700 µm (ratio 1:1 for TCP-P. Biopsies were processed for immunohistochemical analysis of resin-embedded sections. Sections were stained for collagen type I (Col I, alkaline phosphatase (ALP, osteocalcin (OC and bone sialoprotein (BSP. Furthermore, the bone area and biomaterial area fraction were determined histomorphometrically. Cone-beam CT data recorded after SFA and 6 months later were used for calculating the graft volume at these two time points. TCP-P displayed more advantageous surgical handling properties and a significantly greater bone area fraction and smaller biomaterial area fraction. This was accompanied by significantly greater expression of Col I and BSP and in osteoblasts and osteoid and a less pronounced reduction in grafting volume with TCP-P. SFA using both types of materials resulted in formation of sufficient bone volume for facilitating stable dental implant placement with all dental implants having been in function without any complications for 6 years. Since TCP-P displayed superior surgical handling properties and greater bone formation than TCP-G, without the HyAc hydrogel matrix having any adverse effect on bone formation or graft volume stability, TCP-P can be regarded as excellent grafting material for SFA in a clinical setting. The greater bone formation observed with TCP-P may be related to the difference in grain size of the TCP granules and/or the addition of the HyAc.

Inhomogeneous dose escalation increases expected local control for NSCLC patients with lymph node involvement without increased mean lung dose

DEFF Research Database (Denmark)

Nielsen, Tine B; Hansen, Olfred; Schytte, Tine

2014-01-01

in mediastinum, and the thorax wall. The dose was escalated using a TCP model implemented into the planning system. The difference in TCP values between the homogeneous and inhomogeneous plans were evaluated using two different TCP models. RESULTS: Dose escalation was possible for all patients. TCP values based...... to the mediastinum were observed: 2.5 Gy for aorta, 4.4 Gy for the connective tissue, 1.6 Gy for the heart, and 2.6 Gy for trachea + bronchi. CONCLUSION: Increased target doses and TCP values using inhomogeneous dose distributions could be achieved for all patients, regardless of lymph node involvement, tumour stage...

Alpha-tricalcium phosphate cement in the reconstruction of bone defects in rats Cimento de alfa-tricálcio-fosfato na reconstrução de defeitos ósseos em ratos

Directory of Open Access Journals (Sweden)

João Gabriel Souza Pinto

2011-04-01

Full Text Available PURPOSE: To evaluate the ability of a mixture of α-TCP and autogenous bone (AB vs. α-TCP alone and AB alone to promote new bone formation and tissue repair in bone defects. METHODS: Bone defects surgically created in 15 male Wistar rats were divided into four groups: Group I (AB, Group II (α-TCP, Group III (α-TCP+AB assessed by light microscopy, and Group IV (α-TCP+AB assessed by scanning electron microscopy. Bone repair findings were assessed at 30, 60, and 120 days postoperatively. RESULTS: The histological findings obtained in Groups I (p=0.459, II (p=0.368, and III (p=0.459 and at 30 days (p=0.717, 60 days (p=0.717, and 120 days (p=0.779 did not show statistically significant differences. Scanning electron microscopy revealed direct contact between the α-TCP+AB implant and the bone tissue at 120 days. CONCLUSION: The α-TCP implant is effective alternative bone substitutes for the treatment of critical size bone defects.OBJETIVO: Avaliar a capacidade da mistura de α-TCP e osso autógeno (OA Vs somente α-TCP e somente OA em promover a neoformação óssea e reparo tecidual em defeitos ósseos. MÉTODOS: Foram criados cirurgicamente defeitos ósseos em 15 ratos Wistar machos, distribuídos em quatro grupos: Grupo I (OA, Grupo II (α-TCP, Grupo III (α-TCP + OA avaliado por microscopia de luz e Grupo IV (α-TCP + OA avaliado por microscopia eletrônica de varredura. Os resultados da reparação óssea foram avaliados em 30, 60 e 120 dias. RESULTADOS:os achados histológicos obtidos nos grupos I (p = 0,459, II (p = 0,368 e III (p = 0,459 e aos 30 dias (p = 0,717, 60 dias (p = 0,717, e 120 dias (p = 0,779 não apresentaram diferenças estatisticamente significativas. A análise por microscopia eletrônica de varredura revelou contacto direto entre o implante de α-TCP + AO e o tecido ósseo aos 120 dias. CONCLUSÃO: O implante de α-TCP é alternativa eficaz como substitutos ósseos para o tratamento de defeitos ósseos de tamanho crítico.

A Pseudomonas putida Strain Genetically Engineered for 1,2,3-Trichloropropane Bioremediation

OpenAIRE

Samin, Ghufrana; Pavlova, Martina; Arif, M. Irfan; Postema, Christiaan P.; Damborsky, Jiri; Janssen, Dick B.

2014-01-01

1,2,3-Trichloropropane (TCP) is a toxic compound that is recalcitrant to biodegradation in the environment. Attempts to isolate TCP-degrading organisms using enrichment cultivation have failed. A potential biodegradation pathway starts with hydrolytic dehalogenation to 2,3-dichloro-1-propanol (DCP), followed by oxidative metabolism. To obtain a practically applicable TCP-degrading organism, we introduced an engineered haloalkane dehalogenase with improved TCP degradation activity into the DCP...

Performance evaluation of a high-speed switched network for PACS

Science.gov (United States)

Zhang, Randy H.; Tao, Wenchao; Huang, Lu J.; Valentino, Daniel J.

1998-07-01

lower but the patterns were interestingly different from those for ATM. To achieve the optimum throughput in a TCP-based high-speed switched medial imaging network, the size of the TCP socket buffer is the most important parameter to optimize. If the DICOM 3.0 protocol is used, however, the performance gain by tuning system parameters is minimal, particularly if small files are used. Compared to socket-based TCP, the decrease in throughput caused by DICOM 3.0 protocol overhead is significantly larger in a high-speed switched network. This suggests that the protocol itself is the bottleneck in high-speed networks and that the protocol should be fine-tuned to take advantage of the services provided by such networks and not to duplicate them. To design a successful high-speed PACS network, it is important that bandwidth-demanding workstations and servers be on the same subnet and use the same technology so that no routing and data conversions are required.

Covalent interactions of 1,2,3-trichloropropane with hepatic macromolecules: studies in the male F-344 rat.

Science.gov (United States)

Weber, G L; Sipes, I G

1990-07-01

Preliminary investigations into the role of biotransformation in 1,2,3-trichloropropane (TCP)-induced tumor formation have been undertaken. Male F-344 rats were administered 30 mg/kg [14C]TCP (100 microCi/kg) ip and killed 4 hr later. The extent of covalent binding to hepatic protein, DNA, and RNA was 418, 244, and 432 pmol [14C]TCP equivalents/mg, respectively. An in vivo covalent binding time course showed no significant change in [14C]TCP equivalents bound to hepatic DNA (1-48 hr), while binding to protein was maximal by 4 hr and decreased significantly by 48 hr. The binding of TCP-associated radioactivity to hepatic protein and DNA was shown to be cumulative for two and three doses when given 24 hr apart. Pretreatment of animals with phenobarbital caused a decrease while pretreatment with SKF 525-A caused an increase in covalent binding of [14C]TCP equivalents to protein and DNA. Pretreatment of rats with beta-naphthoflavone did not alter the covalent binding of [14C]TCP equivalents to protein or DNA. However, glutathione depletion with L-buthionine-(R,S)-sulfoximine increased binding to protein by 342% while it decreased binding to DNA by 56%. Intraperitoneal administration of TCP also depleted hepatic GSH by 41 and 61% 2 hr after doses of 30 and 100 mg/kg. The in vivo binding data suggest a dual role for GSH in the bioactivation of TCP. It may, in part, be that GSH is involved in the bioactivation and covalent binding of TCP to hepatic DNA. However, it also appears to detoxify a reactive intermediate(s) that binds to protein.

Biomimetic composite coating on rapid prototyped scaffolds for bone tissue engineering.

Science.gov (United States)

Arafat, M Tarik; Lam, Christopher X F; Ekaputra, Andrew K; Wong, Siew Yee; Li, Xu; Gibson, Ian

2011-02-01

The objective of this present study was to improve the functional performance of rapid prototyped scaffolds for bone tissue engineering through biomimetic composite coating. Rapid prototyped poly(ε-caprolactone)/tri-calcium phosphate (PCL/TCP) scaffolds were fabricated using the screw extrusion system (SES). The fabricated PCL/TCP scaffolds were coated with a carbonated hydroxyapatite (CHA)-gelatin composite via biomimetic co-precipitation. The structure of the prepared CHA-gelatin composite coating was studied by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Compressive mechanical testing revealed that the coating process did not have any detrimental effect on the mechanical properties of the scaffolds. The cell-scaffold interaction was studied by culturing porcine bone marrow stromal cells (BMSCs) on the scaffolds and assessing the proliferation and bone-related gene and protein expression capabilities of the cells. Confocal laser microscopy and SEM images of the cell-scaffold constructs showed a uniformly distributed cell sheet and accumulation of extracellular matrix in the interior of CHA-gelatin composite-coated PCL/TCP scaffolds. The proliferation rate of BMSCs on CHA-gelatin composite-coated PCL/TCP scaffolds was about 2.3 and 1.7 times higher than that on PCL/TCP scaffolds and CHA-coated PCL/TCP scaffolds, respectively, by day 10. Furthermore, reverse transcription polymerase chain reaction and Western blot analysis revealed that CHA-gelatin composite-coated PCL/TCP scaffolds stimulate osteogenic differentiation of BMSCs the most, compared with PCL/TCP scaffolds and CHA-coated PCL/TCP scaffolds. These results demonstrate that CHA-gelatin composite-coated rapid prototyped PCL/TCP scaffolds are promising for bone tissue engineering. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Knowledge of Health Effects and Intentions to Quit Among Smokers in India: Findings From the Tobacco Control Policy (TCP India Pilot Survey

Directory of Open Access Journals (Sweden)

Mangesh S. Pednekar

2012-02-01

Full Text Available Awareness of the health risks of smoking is an important factor in predicting smoking-related behaviour; however, little is known about the knowledge of health risks in low-income countries such as India. The present study examined beliefs about the harms of smoking and the impact of health knowledge on intentions to quit among a sample of 249 current smokers in both urban and rural areas in two states (Maharashtra and Bihar from the 2006 TCP India Pilot Survey, conducted by the ITC Project. The overall awareness among smokers in India of the specific health risks of smoking was very low compared to other ITC countries, and only 10% of respondents reported that they had plans to quit in the next six months. In addition, smokers with higher knowledge were significantly more likely to have plans to quit smoking. For example, 26.2% of respondents who believed that smoking cause CHD and only 5.5% who did not believe that smoking causes CHD had intentions to quit (χ2 = 16.348, p < 0.001. Important differences were also found according to socioeconomic factors and state: higher levels of knowledge were found in Maharashtra than in Bihar, in urban compared to rural areas, among males, and among smokers with higher education. These findings highlight the need to increase awareness about the health risks of smoking in India, particularly in rural areas, where levels of education and health knowledge are lower.

Comparative evaluation of clinical efficacy of β-tri calcium phosphate (Septodont-RTR TM alone and in combination with platelet rich plasma for treatment of intrabony defects in chronic periodontitis

Directory of Open Access Journals (Sweden)

Jyostna Pinipe

2014-01-01

Full Text Available Aim: To assess the clinical outcome by comparing β-tri calcium phosphate (Septodont RTR TM along with platelet rich plasma (PRP and β-tri calcium phosphate (β-TCP alone in intrabony defects, by clinical evaluation in a 6-month analysis. Methodology: Ten patients participated in the study. Using a split-mouth design, interproximal bony defects were surgically treated with either platelet rich plasma (PRP combined with β-tri calcium phosphate (β-TCP or β-TCP alone. Plaque Index (PI, Gingival Index, Probing Pocket Depth (PPD, Clinical Attachment Level (CAL were recorded 6 months after surgery. Results: At 6 months after therapy, the PRP combined with β-TCP group showed mean PPD reduction of 2.50, CAL mean gain of 2.60 + 1.43. The β-TCP group showed mean PPD reduction of 2.80 mm, mean CAL gain of 2.60 mm. On intra-group comparison, there was greater PPD reduction and CAL gain at 6 months in both the groups. In intergroup comparison of PRP/β-TCP and β-TCP alone, there was no statistical significant difference observed. (P = 0.55, and 0.87 for PPD and CAL gain. Conclusion: Both therapies resulted in significant PPD reduction, CAL gain. The present study shows that treatment of intrabony periodontal defects with combination of PRP and β-TCP does not have additional improvements when compared with β-TCP alone within 6 months follow-up.

A Chess-Like Game for Teaching Engineering Students to Solve Large System of Simultaneous Linear Equations

Science.gov (United States)

Nguyen, Duc T.; Mohammed, Ahmed Ali; Kadiam, Subhash

2010-01-01

Solving large (and sparse) system of simultaneous linear equations has been (and continues to be) a major challenging problem for many real-world engineering/science applications [1-2]. For many practical/large-scale problems, the sparse, Symmetrical and Positive Definite (SPD) system of linear equations can be conveniently represented in matrix notation as [A] {x} = {b} , where the square coefficient matrix [A] and the Right-Hand-Side (RHS) vector {b} are known. The unknown solution vector {x} can be efficiently solved by the following step-by-step procedures [1-2]: Reordering phase, Matrix Factorization phase, Forward solution phase, and Backward solution phase. In this research work, a Game-Based Learning (GBL) approach has been developed to help engineering students to understand crucial details about matrix reordering and factorization phases. A "chess-like" game has been developed and can be played by either a single player, or two players. Through this "chess-like" open-ended game, the players/learners will not only understand the key concepts involved in reordering algorithms (based on existing algorithms), but also have the opportunities to "discover new algorithms" which are better than existing algorithms. Implementing the proposed "chess-like" game for matrix reordering and factorization phases can be enhanced by FLASH [3] computer environments, where computer simulation with animated human voice, sound effects, visual/graphical/colorful displays of matrix tables, score (or monetary) awards for the best game players, etc. can all be exploited. Preliminary demonstrations of the developed GBL approach can be viewed by anyone who has access to the internet web-site [4]!

Characterization of a newly isolated highly effective 3,5,6-trichloro-2-pyridinol degrading strain Cupriavidus pauculus P2.

Science.gov (United States)

Cao, Li; Liu, Hongming; Zhang, Hao; Huang, Ke; Gu, Tao; Ni, Haiyan; Hong, Qing; Li, Shunpeng

2012-09-01

A bacterial strain P2 capable of degrading 3,5,6-trichloro-2-pyridinol (TCP) was isolated and characterized. Phylogenetic analysis based on 16S rRNA gene sequence indicated that it belonged to the genus of Cupriavidus, because it showed the highest sequence similarity to Cupriavidus pauculus LMG 3413(T) (99.7 %) and DNA-DNA relatedness value between strain P2 and C. pauculus LMG 3413(T) was 76.8 %. In combination with morphological, physiological and biochemical characters, strain P2 was identified as C. pauculus. It could use TCP as the sole carbon source and energy source for its growth. It showed a high average degradation rate of 10 mg/L h in mineral salt medium amended with TCP (50-800 mg/L). During TCP degradation, chloridion was released into the medium in two obvious discontinuous stages. Along with this, two colorful metabolites were produced. Finally, the molarity of the total released chloridion was three times that of the initial TCP in the medium. This is the first report of TCP-degrading strain from the genus of Cupriavidus and the detection of two colorful metabolites during TCP degradation. Strain P2 might be a promising candidate for its application in the bioremediation of TCP-polluted environments.

Genetic and phenotypic heterogeneity in tropical calcific pancreatitis.

Science.gov (United States)

Paliwal, Sumit; Bhaskar, Seema; Chandak, Giriraj R

2014-12-14

Tropical calcific pancreatitis (TCP) is a form of chronic non-alcoholic pancreatitis initially reported in the developing parts of the tropical world. The clinical phenotype of TCP has undergone marked changes since its first description in 1968. The disease is now seen in relatively older people with less severe symptoms. In addition, there are varying reports on the proportion of cases presenting with imaging abnormalities like calcification, ductal dilation, and glandular atrophy. Significant progress has also been made in understanding the etiopathology of TCP. The role of malnutrition and cassava toxicity in its pathogenesis is disproven and few studies have focused on the role of micronutrient deficiency and oxidative stress in the etiopathogenesis of TCP. Emerging evidence support an important role for genetic risk factors in TCP. Several studies have shown that, rather than mutations in trypsinogens, variants in serine protease inhibitor kazal type 1, cathepsin B, chymotrypsin C, cystic fibrosis transmembrane regulator, and carboxypeptidase A1, predict risk of TCP. These studies also provided evidence of mutational heterogeneity between TCP and chronic pancreatitis in Western populations. The current review summarizes recent advances that have implications in the understanding of the pathophysiology and thus, heterogeneity in genotype-phenotype correlations in TCP.

Coding and transmission of subband coded images on the Internet

Science.gov (United States)

Wah, Benjamin W.; Su, Xiao

2001-09-01

Subband-coded images can be transmitted in the Internet using either the TCP or the UDP protocol. Delivery by TCP gives superior decoding quality but with very long delays when the network is unreliable, whereas delivery by UDP has negligible delays but with degraded quality when packets are lost. Although images are delivered currently over the Internet by TCP, we study in this paper the use of UDP to deliver multi-description reconstruction-based subband-coded images. First, in order to facilitate recovery from UDP packet losses, we propose a joint sender-receiver approach for designing optimized reconstruction-based subband transform (ORB-ST) in multi-description coding (MDC). Second, we carefully evaluate the delay-quality trade-offs between the TCP delivery of SDC images and the UDP and combined TCP/UDP delivery of MDC images. Experimental results show that our proposed ORB-ST performs well in real Internet tests, and UDP and combined TCP/UDP delivery of MDC images provide a range of attractive alternatives to TCP delivery.

Effect of Zn and Mg in tricalcium phosphate and in culture medium on apoptosis and actin ring formation of mature osteoclasts

International Nuclear Information System (INIS)

Li Xia; Ito, Atsuo; Sogo, Yu; Senda, Koji; Yamazaki, Atsushi

2008-01-01

This study investigated the resorptive activity of osteoclasts on tricalcium phosphate (TCP), zinc-containing tricalcium phosphate (ZnTCP) and magnesium-containing tricalcium phosphate (MgTCP) ceramics in different Zn- or Mg-containing culture media. On the TCP ceramic, an increase in Zn ions in the culture medium within the range between 0.3 and 6.8 ppm significantly induced an increase in osteoclast apoptosis and a decrease in actin ring formation. However, even a high level of Mg ions up to 100 ppm in the culture medium was unlikely to induce an increase in osteoclast apoptosis. Mg ions in the MgTCP ceramics have no effect on osteoclast apoptosis and actin ring formation. There was almost no significant difference in osteoclast apoptosis and actin ring formation between ZnTCP and MgTCP ceramics which have the same solubility and dissolution rates. It is indicated that only an increase in Zn level outside resorption lacuna has an inhibitory effect on osteoclast resorption and that an increase in Zn level inside resorption lacuna could not influence the osteoclast activity.

Effects of substitute coated with hyaluronic acid or poly-lactic acid on implant fixation. Experimental study in ovariectomized and glucocorticoid treated sheep

DEFF Research Database (Denmark)

Andreasen, Christina M; Ding, Ming; Andersen, Thomas L

2018-01-01

Investigated in healthy animal models, hyaluronic acid (HyA) and poly-D,L -lactic acid (PDLLA) demonstrate osteoconductive properties when coated onto hydroxyapatite (HA) and β-tricalcium phosphate (βTCP) scaffolds. In this study, we examined the efficacy of HA/βTCP granules coated with HyA or PD...... formation, HyA and PDDLA are indeed considered valuable as new coating materials for composite ceramics when tested in a sheep model - even in bones of a compromised quality.......Investigated in healthy animal models, hyaluronic acid (HyA) and poly-D,L -lactic acid (PDLLA) demonstrate osteoconductive properties when coated onto hydroxyapatite (HA) and β-tricalcium phosphate (βTCP) scaffolds. In this study, we examined the efficacy of HA/βTCP granules coated with Hy...... allograft obtained from a healthy donor sheep (control), pure HA/βTCP, HA/βTCP-HyA or HA/βTCP-PDLLA. After 12 weeks, the bone formation adjacent to the implant surface was evaluated by histology and histomorphometry, while the implant fixation was measured by a push-out test. The investigation showed a bone...

'Anthropological mutilation' and the reordering of Cameroonian ...

African Journals Online (AJOL)

I argue in this article that the postcolonial existential wound, otherwise referred to by Eboussi Boulaga as the anthropological mutilation, represents the intertextual nexus that bridges the generational gap in Francophone Cameroonian literature. The tragic malaise, rooted in absurdity and the dire state of the postcolonial ...

'Anthropological mutilation' and the reordering of Cameroonian ...

African Journals Online (AJOL)

2016-03-28

Mar 28, 2016 ... It takes the form of madness, incestuous rape, or child abandonment. ... the analysis will show, to push anticolonial memory further to the edges of mar- ginality. ... evil, long incarnated by colonial or neocolonial authorities, is now ... administration is represented in terms of a flawed sexuality” (Tcheuyap 186).

Re-Ordering Structural Dimensions for Nigerian Organizations ...

African Journals Online (AJOL)

The organization structure (OS) reflects the interface of the dimensions of the OS, the model in place and the mix of determinants of OS. This paper focuses on the organization structure (OS) to find out, not just the consistency of the structural properties with the OS but also the potentials of OS oriented towards the realization ...

Modeling and analysis for determining optimal suppliers under stochastic lead times

DEFF Research Database (Denmark)

Abginehchi, Soheil; Farahani, Reza Zanjirani

2010-01-01

systems. The item acquisition lead times of suppliers are random variables. Backorder is allowed and shortage cost is charged based on not only per unit in shortage but also per time unit. Continuous review (s,Q) policy has been assumed. When the inventory level depletes to a reorder level, the total...... order is split among n suppliers. Since the suppliers have different characteristics, the quantity ordered to different suppliers may be different. The problem is to determine the reorder level and quantity ordered to each supplier so that the expected total cost per time unit, including ordering cost...

Classic Maya civilization collapse related to modest reduction in precipitation

Science.gov (United States)

Medina-Elizalde, M.; Rohling, E. J.

2013-05-01

The disintegration of the Classic Maya civilization during the Terminal Classic Period (TCP) in the Yucatán Peninsula (YP) and Central America was a complex process that occurred over a ~200-year interval and involved a catastrophic depopulation of the region. While it is well established that the civilization collapse coincided with widespread episodes of drought, their nature and severity remain enigmatic. We present a quantitative analysis that offers a coherent interpretation for four of the most detailed paleoclimate records of the event. The underlying processes driving the patterns and amplitudes of these environmental records during the TCP are evaluated with an isotope mass balance model set up for Lake Chichancanab, located in the YP. We use our hydrological-isotope model (i) to test whether the TCP droughts reflect a persistent summer season southern shift of the intertropical convergence zone and its associated belt of convective activity, away from the YP, and (2) to simulate the development of Lake Chichancanab as a function of weaker perturbations to summer precipitation as reflected by a stalagmite d18O-derived rainfall record from the YP. We conclude that the droughts occurring during the disintegration of the Maya civilization represented up to 40% reduction in annual precipitation, likely due to a reduction in summer season tropical cyclone frequency/intensity. Archaeological and Paleoclimatic records from the Yucatan Peninsula

Low temperature preparation of α-tricalcium phosphate and its mechanical properties

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Song Wang

2017-06-01

Full Text Available In this work, α-tricalcium phosphate (α-TCP was successfully prepared by the thermal transformation of amorphous calcium phosphate (ACP precursor. β-cyclodextrin (β-CD was used for preparation of ACP precursor and played an important role in designing its special structure. The phase composition and microstructures of the obtained α-TCP at different annealing temperature were analysed by X-ray diffraction and scanning electron microscope, and confirmed that α-TCP can be prepared at 650°C for 3 h using ACP as precursor, which is much lower than the phase transition temperature of α-TCP. Mechanical properties were tested 24 h after mixing the obtained α-TCP with 30 wt.% of deionised water. The compressive strength and the flexural strength were 26.4MPa and 12.0MPa, respectively. The flexural strength was higher than that of α-TCP prepared by other methods.

Cytotoxicity detection of poly(lactic-co-glycolic acid/tricalcium phosphate

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Meng SUN

2011-12-01

Full Text Available Objective To detecte the cytotoxicity of the PLGA/TCP(poly(lactic-co-glycolic acid/Tricalcium phosphate composite that based on the precedent experiments conducted in Tsinghua University.Methods Compared with the PLGA scaffold material,observated the surface and interior structure of the PLGA/TCP scaffold material by SEM(scanning electron microscope,the surface and interior of PLGA/TCP scaffold material appeared to be homogeneous porous under SEM,with fairly even porosity distribution.The pore diameter was approximately 400μm.The interpenetrative micro-pores were scattered over bigger pores’ periphery with approximately circular contour and 3~5 μm in diameter.These pores were interpenetrative,the average factor of porosity was 89.6%.And which selected rat L929 cell strain,and detected the cytotoxicity of the PLGA/TCP composite in vitro by MTT method.Results The surface and interior of PLGA/TCP scaffold material appeared to be homogeneous porous under SEM,with fairly even porosity distribution.The pore diameter was approximately 400μm.The interpenetrative micro-pores were scattered over bigger pores’ periphery with approximately circular contour and 3~5 μm in diameter.These pores were interpenetrative,the average factor of porosity was 89.6%.On rat L929 cell strain,used MTT Method to detect the cytotoxicity of the composite PLGA/ TCP in vitro,the result showed that the cytotoxicity of the PLGA/TCP composite was level I,according to the criterion,it can be considered as non cytotoxic.Conclusion This research has proved that the PLGA/TCP compound scaffold material has a more homogeneous structure,with the vesicular interior and the structure of PLGA/TCP composite is similar to natural bone trabecula,PLGA/TCP is non cytotoxicity,which satisfy the basic requirement of biological material application and provides a good experimental foundation for repairing autologous bone defect in the near future.

The impact of microscopic disease on the tumor control probability in non-small-cell lung cancer

International Nuclear Information System (INIS)

Siedschlag, Christian; Boersma, Liesbeth; Loon, Judith van; Rossi, Maddalena; Baardwijk, Angela van; Gilhuijs, Kenneth; Stroom, Joep

2011-01-01

Purpose: To indicate which clinical target volume (CTV) margin (if any) is needed for an adequate treatment of non-small-cell lung cancer (NSCLC) using either 3D conformal or stereotactic radiotherapy, taking the distribution of the microscopic disease extension (MDE) into account. Methods and materials: On the basis of the linear-quadratic biological model, a Monte-Carlo simulation was used to study the impact of MDE and setup deviations on the tumor control probability (TCP) after typical 3D conformal and stereotactic irradiation techniques. Setup deviations were properly accounted for in the planning target volume (PTV) margin. Previously measured distributions of MDE outside the macroscopic tumor in NSCLC patients were used. The dependence of the TCP on the CTV margins was quantified. Results: The presence of MDE had a demonstratable influence on the TCP in both the 3D conformal and the stereotactic technique when no CTV margins were employed. The impact of MDE on the TCP values was greater in the 3D conformal scenario (67% TCP with MDE; 84% TCP without MDE) than for stereotactic radiotherapy (91% TCP with MDE; 100% TCP without MDE). Accordingly, an increase of the CTV margin had the greatest impact for the 3D conformal technique. Larger setup errors, with appropriate PTV margins, lead to an increase in TCP for both techniques, showing the interdependence of CTV and PTV margins. Conclusions: MDE may not always be eradicated by the beam penumbra or existing PTV margins using either 3D conformal or stereotactic radiotherapy. Nonetheless, TCP modeling indicates an overall local control rate above 90% for the stereotactic technique, while a non-zero CTV margin is recommended for better local control of MDE when using the 3D conformal technique.

{sup 18}F-Fluorodeoxyglucose/Positron Emission Tomography Predicts Patterns of Failure After Definitive Chemoradiation Therapy for Locally Advanced Non-Small Cell Lung Cancer

Energy Technology Data Exchange (ETDEWEB)

Ohri, Nitin, E-mail: ohri.nitin@gmail.com [Department of Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York (United States); Bodner, William R. [Department of Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York (United States); Halmos, Balazs; Cheng, Haiying; Perez-Soler, Roman [Department of Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York (United States); Keller, Steven M. [Department of Cardiothoracic Surgery, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York (United States); Kalnicki, Shalom; Garg, Madhur [Department of Radiation Oncology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York (United States)

2017-02-01

Background: We previously reported that pretreatment positron emission tomography (PET) identifies lesions at high risk for progression after concurrent chemoradiation therapy (CRT) for locally advanced non-small cell lung cancer (NSCLC). Here we validate those findings and generate tumor control probability (TCP) models. Methods: We identified patients treated with definitive, concurrent CRT for locally advanced NSCLC who underwent staging {sup 18}F-fluorodeoxyglucose/PET/computed tomography. Visible hypermetabolic lesions (primary tumors and lymph nodes) were delineated on each patient's pretreatment PET scan. Posttreatment imaging was reviewed to identify locations of disease progression. Competing risks analyses were performed to examine metabolic tumor volume (MTV) and radiation therapy dose as predictors of local disease progression. TCP modeling was performed to describe the likelihood of local disease control as a function of lesion size. Results: Eighty-nine patients with 259 hypermetabolic lesions (83 primary tumors and 176 regional lymph nodes) met the inclusion criteria. Twenty-eight patients were included in our previous report, and the remaining 61 constituted our validation cohort. The median follow-up time was 22.7 months for living patients. In 20 patients, the first site of progression was a primary tumor or lymph node treated with radiation therapy. The median time to progression for those patients was 11.5 months. Data from our validation cohort confirmed that lesion MTV predicts local progression, with a 30-month cumulative incidence rate of 23% for lesions above 25 cc compared with 4% for lesions below 25 cc (P=.008). We found no evidence that radiation therapy dose was associated with local progression risk. TCP modeling yielded predicted 30-month local control rates of 98% for a 1-cc lesion, 94% for a 10-cc lesion, and 74% for a 50-cc lesion. Conclusion: Pretreatment FDG-PET identifies lesions at risk for progression after CRT for

Structural and mechanical characterization of boron doped biphasic calcium phosphate produced by wet chemical method and subsequent thermal treatment

Energy Technology Data Exchange (ETDEWEB)

Albayrak, Onder, E-mail: albayrakonder@mersin.edu.tr

2016-03-15

In the current study, boron doped biphasic calcium phosphate bioceramics consisting of a mixture of boron doped hydroxyapatite (BHA) and beta tricalcium phosphate (β-TCP) of varying BHA/β-TCP ratios were obtained after sintering stage. The effects of varying boron contents and different sintering temperatures on the BHA/β-TCP ratios and on the sinterability of the final products were investigated. Particle sizes and morphologies of the obtained precipitates were determined using SEM. XRD and FTIR investigation were conducted to detect the boron formation in the structure of HA and quantitative analysis was performed to determine the BHA/β-TCP ratio before and after sintering stage. In order to determine the sinterability of the obtained powders, pellets were prepared and sintered; the rates of densification were calculated and obtained results were correlated by SEM images. Also Vickers microhardness values of the sintered samples were determined. The experimental results verified that boron doped hydroxyapatite powders were obtained after sintering stage and the structure consists of a mixture of BHA and β-TCP. As the boron content used in the precipitation stage increases, β-TCP content of the BHA/β-TCP ratio increases but sinterability, density and microhardness deteriorate. As the sintering temperature increases, β-TCP content, density and microhardness of the samples increase and sinterability improves. - Highlights: • This is the first paper about boron doped biphasic calcium phosphate bioceramics. • Boron doping affects the structural and mechanical properties. • BHA/β-TCP ratio can be adjustable with boron content and sintering temperature.

Sintering and robocasting of beta-tricalcium phosphate scaffoldsfor orthopaedic applications

Energy Technology Data Exchange (ETDEWEB)

Miranda, Pedro; Saiz, Eduardo; Gryn Karol; Tomsia, Antoni P.

2005-11-01

{beta}-tricalcium phosphate ({beta}-TCP) scaffolds with designed, three-dimensional (3-D) geometry and mesoscale porosity have been fabricated by direct-write assembly (robocasting) techniques. Concentrated {beta}-TCP inks with suitable viscoelastic properties were developed to enable the fabrication of the complex 3-D structures. A comprehensive study of the sintering behavior of TCP as a function of the calcium content in the starting powder was also carried out, and the optimal heat treatment for fabricating scaffolds with dense {beta}-TCP rods has been determined. Such analysis provides clues to controlling the microstructure of the fabricated structures and, therefore, enabling the fabrication by robocasting of TCP scaffolds with tailored performance for bone tissue engineering applications.

Chaperonin-Containing t-Complex Protein-1 Subunit β as a Possible Biomarker for the Phase of Glomerular Hyperfiltration of Diabetic Nephropathy

Directory of Open Access Journals (Sweden)

Chung-Ze Wu

2015-01-01

Full Text Available In cell model, we discovered the association between chaperonin-containing t-complex polypeptide 1 subunit β (TCP-1β and early diabetic nephropathy (DN. In this study, we further explored the relationships between TCP-1β and type 2 diabetic mellitus (DM. To mimic the clinical hyperfiltration state, a type 2 DM mice model was established by feeding a high-fat diet in combination with treatment of streptozotocin and nicotinamide. Blood and urine were collected to determine creatinine clearance (Ccr, and kidney tissues were harvested for evaluation of TCP-1β expression by immunohistochemistry and Western blot. Meanwhile, clinical subjects of healthy controls and type 2 DM were recruited to strengthen the evidence with urine TCP-1β. Results showed that Ccr and the expression of TCP-1β in kidney were significantly higher one week after hyperglycemia development, suggesting that the hyperfiltration state was successfully established in the mice model. TCP-1β was expressed predominantly on renal tubules. By using the estimated glomerular filtration rate to index progression in clinical investigation, urine TCP-1β level was associated with the hyperfiltration phase in type 2 DM patients. Conclusively, we confirmed that TCP-1β is a possible biomarker for early nephropathy of type 2 DM, but further mechanistic study to elucidate its cause and pathway is needed.

Implantation of tetrapod-shaped granular artificial bones or β-tricalcium phosphate granules in a canine large bone-defect model.

Science.gov (United States)

Choi, Sungjin; Liu, I-Li; Yamamoto, Kenichi; Honnami, Muneki; Sakai, Takamasa; Ohba, Shinsuke; Echigo, Ryosuke; Suzuki, Shigeki; Nishimura, Ryouhei; Chung, Ung-Il; Sasaki, Nobuo; Mochizuki, Manabu

2014-03-01

We investigated biodegradability and new bone formation after implantation of tetrapod-shaped granular artificial bone (Tetrabone®) or β-tricalcium phosphate granules (β-TCP) in experimental critical-size defects in dogs, which were created through medial and lateral femoral condyles. The defect was packed with Tetrabone® (Tetrabone group) or β-TCP (β-TCP group) or received no implant (control group). Computed tomography (CT) was performed at 0, 4 and 8 weeks after implantation. Micro-CT and histological analysis were conducted to measure the non-osseous tissue rate and the area and distribution of new bone tissue in the defect at 8 weeks after implantation. On CT, β-TCP was gradually resorbed, while Tetrabone® showed minimal resorption at 8 weeks after implantation. On micro-CT, non-osseous tissue rate of the control group was significantly higher compared with the β-TCP and Tetrabone groups (Pbone tissue of the β-TCP group was significantly greater than those of the Tetrabone and control groups (Pbone distribution of the Tetrabone group was significantly greater than those of the β-TCP and control groups (Pbone defects in dogs.

Synthesis and characterization of new crystalline mesoporous beta-tricalcium phosphate nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Silva, F.R.O.; Yoshito, W.K.; Cosentino, I.C.; Bressiani, A.H.A.; Lima, N.B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2016-07-01

Full text: Calcium phosphates, including hydroxyapatite [HA, Ca10 (PO4)6(OH)2] and beta-tricalcium phosphate [B-TCP, Ca3(PO4)2], are the main mineral component of bone tissue and teeth. The synthetic calcium phosphates are of special interest in medicine because of their biocompatibility, bioactivity and non-toxicity. B-TCP is advantageous to HA for drug delivery system due to their high solubility and controllable bioresorption rate. To obtain B-TCP, the literature reports the transformation of calcium deficient hydroxyapatite (CDHA) to ?-TCP since it couldnot be synthesized directly in aqueous solution, until now. For the first time, B-TCP have been successfully synthesized by wet precipitation method at room temperature with a Ca/P molar ratio equal to 1.5 and pH at 6. The present work is concerned with the preparation of B-TCP and it characterization through XRD, BET and TEM analysis. The results showed well-characterized peaks of crystalline pure B-TCP (JCPDS 09-0169) for the dried powder, with a high BET surface area of 574 ± 7 (m2/g). The TEM micrographs exhibits mesoporous structure, which is suitable as a drug carrier. (author)

Design, Implementation and Evaluation of Congestion Control Mechanism for Video Streaming

OpenAIRE

Hiroshi Noborio; Hiroyuki Hisamatsu; Hiroki Oda

2011-01-01

In recent years, video streaming services over TCP, such as YouTube, have become more and more popular. TCP NewReno, the current TCP standard, performs greedy congestion control, which increases the congestion window size until packet loss occurs. Therefore, because TCP transmits data at a much higher rate than the video playback rate, the probability of packet loss in the network increases, which in turn takes bandwidth from other network traffic. In this paper, we propose a new transport-la...

Effects of 3D-Printed Polycaprolactone/β-Tricalcium Phosphate Membranes on Guided Bone Regeneration.

Science.gov (United States)

Shim, Jin-Hyung; Won, Joo-Yun; Park, Jung-Hyung; Bae, Ji-Hyeon; Ahn, Geunseon; Kim, Chang-Hwan; Lim, Dong-Hyuk; Cho, Dong-Woo; Yun, Won-Soo; Bae, Eun-Bin; Jeong, Chang-Mo; Huh, Jung-Bo

2017-04-25

This study was conducted to compare 3D-printed polycaprolactone (PCL) and polycaprolactone/β-tricalcium phosphate (PCL/β-TCP) membranes with a conventional commercial collagen membrane in terms of their abilities to facilitate guided bone regeneration (GBR). Fabricated membranes were tested for dry and wet mechanical properties. Fibroblasts and preosteoblasts were seeded into the membranes and rates and patterns of proliferation were analyzed using a kit-8 assay and by scanning electron microscopy. Osteogenic differentiation was verified by alizarin red S and alkaline phosphatase (ALP) staining. An in vivo experiment was performed using an alveolar bone defect beagle model, in which defects in three dogs were covered with different membranes. CT and histological analyses at eight weeks after surgery revealed that 3D-printed PCL/β-TCP membranes were more effective than 3D-printed PCL, and substantially better than conventional collagen membranes in terms of biocompatibility and bone regeneration and, thus, at facilitating GBR.

Effects of 3D-Printed Polycaprolactone/β-Tricalcium Phosphate Membranes on Guided Bone Regeneration

Directory of Open Access Journals (Sweden)

Jin-Hyung Shim

2017-04-01

Full Text Available This study was conducted to compare 3D-printed polycaprolactone (PCL and polycaprolactone/β-tricalcium phosphate (PCL/β-TCP membranes with a conventional commercial collagen membrane in terms of their abilities to facilitate guided bone regeneration (GBR. Fabricated membranes were tested for dry and wet mechanical properties. Fibroblasts and preosteoblasts were seeded into the membranes and rates and patterns of proliferation were analyzed using a kit-8 assay and by scanning electron microscopy. Osteogenic differentiation was verified by alizarin red S and alkaline phosphatase (ALP staining. An in vivo experiment was performed using an alveolar bone defect beagle model, in which defects in three dogs were covered with different membranes. CT and histological analyses at eight weeks after surgery revealed that 3D-printed PCL/β-TCP membranes were more effective than 3D-printed PCL, and substantially better than conventional collagen membranes in terms of biocompatibility and bone regeneration and, thus, at facilitating GBR.

submitter Optimizing the data-collection time of a large-scale data-acquisition system through a simulation framework

CERN Document Server

Colombo, Tommaso; Garcìa, Pedro Javier; Vandelli, Wainer

2016-01-01

The ATLAS detector at CERN records particle collision “events” delivered by the Large Hadron Collider. Its data-acquisition system identifies, selects, and stores interesting events in near real-time, with an aggregate throughput of several 10 GB/s. It is a distributed software system executed on a farm of roughly 2000 commodity worker nodes communicating via TCP/IP on an Ethernet network. Event data fragments are received from the many detector readout channels and are buffered, collected together, analyzed and either stored permanently or discarded. This system, and data-acquisition systems in general, are sensitive to the latency of the data transfer from the readout buffers to the worker nodes. Challenges affecting this transfer include the many-to-one communication pattern and the inherently bursty nature of the traffic. The main performance issues brought about by this workload are addressed in this paper, focusing in particular on the so-called TCP incast pathology. Since performing systematic stud...

Modeling a Large Data Acquisition Network in a Simulation Framework

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00337030; The ATLAS collaboration; Froening, Holger; Garcia, Pedro Javier; Vandelli, Wainer

2015-01-01

The ATLAS detector at CERN records particle collision “events” delivered by the Large Hadron Collider. Its data-acquisition system is a distributed software system that identifies, selects, and stores interesting events in near real-time, with an aggregate throughput of several 10 GB/s. It is a distributed software system executed on a farm of roughly 2000 commodity worker nodes communicating via TCP/IP on an Ethernet network. Event data fragments are received from the many detector readout channels and are buffered, collected together, analyzed and either stored permanently or discarded. This system, and data-acquisition systems in general, are sensitive to the latency of the data transfer from the readout buffers to the worker nodes. Challenges affecting this transfer include the many-to-one communication pattern and the inherently bursty nature of the traffic. In this paper we introduce the main performance issues brought about by this workload, focusing in particular on the so-called TCP incast pathol...

Abscisic acid signaling is controlled by a BRANCHED1/HD-ZIP I cascade in Arabidopsis axillary buds.

Science.gov (United States)

González-Grandío, Eduardo; Pajoro, Alice; Franco-Zorrilla, José M; Tarancón, Carlos; Immink, Richard G H; Cubas, Pilar

2017-01-10

Shoot-branching patterns determine key aspects of plant life and are important targets for crop breeding. However, we are still largely ignorant of the genetic networks controlling locally the most important decision during branch development: whether the axillary bud, or branch primordium, grows out to give a lateral shoot or remains dormant. Here we show that, inside the buds, the TEOSINTE BRANCHED1, CYCLOIDEA, PCF (TCP) transcription factor BRANCHED1 (BRC1) binds to and positively regulates the transcription of three related Homeodomain leucine zipper protein (HD-ZIP)-encoding genes: HOMEOBOX PROTEIN 21 (HB21), HOMEOBOX PROTEIN 40 (HB40), and HOMEOBOX PROTEIN 53 (HB53). These three genes, together with BRC1, enhance 9-CIS-EPOXICAROTENOID DIOXIGENASE 3 (NCED3) expression, lead to abscisic acid accumulation, and trigger hormone response, thus causing suppression of bud development. This TCP/HD-ZIP genetic module seems to be conserved in dicot and monocotyledonous species to prevent branching under light-limiting conditions.

Six virtual inches to the left: The problem with IPng

Energy Technology Data Exchange (ETDEWEB)

Carlson, R. [Argonne National Lab., IL (United States); Ficarella, D. [Motorola (United States)

1994-05-01

This memo describes an Internet information track protocol for the Internet community. It proposes that a locator address (TA) be assigned to Transmission Control Protocol (TCP). The purpose of this TA is to uniquely identify an Internet node without specifing any routing information. This new version of TCP would contain support for high bandwidth-delay networks. Support for multiple network layer (Internet Protocol) protocols is also possible with this new TCP. Distribution of this document is unlimited. This RFC suggests that a new version of TCP be developed (TCPv11) and deployed. This version of TCP would contain a globally unique transport protocol address (TA). Assiging an address to TCP would allow for the support of multiple network layer protocols (IPng`s). The Ta would identify the location of an Internet node. The IPng layer would provide routing information to the Internet. Seperating the location and routing functions will greatly increase the versitily of the Internet.

Mechanical properties of calcium phosphate cements obtained by solution combustion synthesis

Energy Technology Data Exchange (ETDEWEB)

Volkmer, Tiago M.; Barreiro, Oscar; Souza, Vania Caldas; Santos, Luis Alberto dos, E-mail: tiagovolkmer@gmail.com, E-mail: oscarbafer@hotmail.com, E-mail: vania.souza@ufrgs.br, E-mail: luis.santos@ufrgs.br [Universidade Federal do Rio Grande do Sul (UFRS), Porto Alegre, RS (Brazil). Laboratorio de Biomateriais

2009-07-01

Bioceramics based on calcium phosphates, especially hydroxyapatite and tricalcium phosphates (TCP) are the most used biomaterials as bone substitutes. The objective of this work is to evaluate the mechanical properties of α-tricalcium phosphate (α-TCP) synthesized by the solution combustion method. The solution combustion synthesis (SCS) can be considered as faster and simpler as other methods, furthermore it allows the obtainment of high purity α-TCP. In the calcium phosphates (CPC), α-TCP reacts with water forming needle like HA, which restrain the movement of grains, increasing mechanical resistance. In the present paper the influence of particle size on mechanical properties of α-TCP cements were evaluated. The α-TCP powder were characterized by XRD, TEM, BET and laser diffraction to asses particle size while the CPC bodies by SEM, Arquimedes method and compression tests. Increasing the milling time, the particle size decreases, resulting in samples with less porosity and consequently with higher compression resistance. (author)

A Lossless Network for Data Acquisition

OpenAIRE

Jereczek, Grzegorz Edmund; Lehmann Miotto, Giovanna

2016-01-01

The bursty many-to-one communication pattern, typical for data acquisition systems, is particularly demanding for commodity TCP/IP and Ethernet technologies. We expand the study of lossless switching in software running on commercial-off-the-shelf servers, using the ATLAS experiment as a case study. In this paper we extend the popular software switch, Open vSwitch, with a dedicated, throughput-oriented buffering mechanism for data acquisition. We compare the performance under heavy congestion...

Effects of 3D-Printed Polycaprolactone/?-Tricalcium Phosphate Membranes on Guided Bone Regeneration

OpenAIRE

Shim, Jin-Hyung; Won, Joo-Yun; Park, Jung-Hyung; Bae, Ji-Hyeon; Ahn, Geunseon; Kim, Chang-Hwan; Lim, Dong-Hyuk; Cho, Dong-Woo; Yun, Won-Soo; Bae, Eun-Bin; Jeong, Chang-Mo; Huh, Jung-Bo

2017-01-01

This study was conducted to compare 3D-printed polycaprolactone (PCL) and polycaprolactone/β-tricalcium phosphate (PCL/β-TCP) membranes with a conventional commercial collagen membrane in terms of their abilities to facilitate guided bone regeneration (GBR). Fabricated membranes were tested for dry and wet mechanical properties. Fibroblasts and preosteoblasts were seeded into the membranes and rates and patterns of proliferation were analyzed using a kit-8 assay and by scanning electron micro...

Thrombocytopenia during pregnancy in women with HIV infection ...

African Journals Online (AJOL)

Background. Thrombocytopenia (TCP) complicates 5 - 8% of pregnancies. Most cases of TCP are gestational, and the condition is usually mild and occurs in the latter part of pregnancy. Apart from pregnancy-associated medical complications such as pre-eclampsia, HIV infection is a recognised cause of TCP, and a ...

Network Analysis with SiLK

Science.gov (United States)

2015-01-06

Carnegie Mellon University rwcut Default Display By default • sIP , sPort • dIP, dPort • protocol • packets, bytes • flags • sTime, eTime, duration...TCP/IP SOCKET IP address: 10.0.0.1 L4 protocol : TCP High-numbered ephemeral port # TCP/IP SOCKET IP address: 203.0.113.1 L4 protocol : TCP Low-numbered...Fields found to be useful in analysis: • source address, destination address • source port, destination port (Internet Control Message Protocol

Tricritical point of a ferromagnetic transition in UGe2

International Nuclear Information System (INIS)

Kabeya, N; Iijima, R; Osaki, E; Ban, S; Imura, K; Deguchi, K; Sato, N K; Aso, N; Homma, Y; Shiokawa, Y

2010-01-01

Thermal expansion and magnetostriction measurements of the superconducting ferromagnet UGe 2 under pressure were carried out. The temperature dependence of the thermal expansion coefficient shows a peak at the Curie temperature. When pressure is varied, the peak exhibits a maximum in the vicinity of a tricritical point (TCP), which separates the second-order phase transition from the first-order transition. From results of these measurements, we first construct the magnetic phase diagram including the TCP (P TCP ∼ 12.5 kbar). We also show that two lines characterizing the metamagnetism and the magnetic susceptibility emerge from the TCP. We argue that these magnetic properties in the vicinity of the TCP can be understood within a phenomenological frame of spin fluctuations.

Osteogenesis and angiogenesis properties of dental pulp cell on novel injectable tricalcium phosphate cement by silica doped.

Science.gov (United States)

Su, Ying-Fang; Lin, Chi-Chang; Huang, Tsui-Hsien; Chou, Ming-Yung; Yang, Jaw-Ji; Shie, Ming-You

2014-09-01

β-Tricalcium phosphate (β-TCP) is an osteoconductive material in clinical. In this study, we have doped silica (Si) into β-TCP and enhanced its bioactive and osteostimulative properties. To check its effectiveness, a series of Si-doped with different ratios were prepared to make new bioactive and biodegradable biocomposites for bone repair. Formation of the diametral tensile strength, ions released and weight loss of cements was considered after immersion. In addition, we also examined the behavior of human dental pulp cells (hDPCs) cultured on Si-doped β-TCP cements. The results showed that setting time and injectability of the Si-doped β-TCP cements were decreased as the Si content was increased. At the end of the immersion point, weight losses of 30.1%, 36.9%, 48.1%, and 55.3% were observed for the cement doping 0%, 10%, 20%, and 30% Si into β-TCP cements, respectively. In vitro cell experiments show that the Si-rich cements promote human dental pulp cell (hDPC) proliferation and differentiation. However, when the Si-doped in the cement is more than 20%, the amount of cells and osteogenesis protein of hDPCs was stimulated by Si released from Si-doped β-TCP cements. The degradation of β-TCP and osteogenesis of Si gives a strong reason to believe that these Si-doped β-TCP cements may prove to be promising bone repair materials. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of hypoxia-ischemia and MK-801 treatment on the binding of a phencyclidine analogue in the developing rat brain

International Nuclear Information System (INIS)

Silverstein, F.S.; McDonald, J.W. III; Bommarito, M.; Johnston, M.V.

1990-01-01

The phencyclidine analogue [ 3 H](1-[2-thienyl]cyclohexyl)piperidine ( 3 H-TCP) binds to the ion channel associated with the N-methyl-D-aspartate receptor channel complex. In vitro autoradiography indicates that the distribution of 3 H-TCP binding in brain closely parallels that of [ 3 H]glutamate binding to the N-methyl-D-aspartate receptor. In nine 7-day-old rats, an acute focal hypoxic-ischemic insult produced by unilateral carotid artery ligation and subsequent exposure to 8% oxygen acutely reduced 3 H-TCP binding ipsilateral to the ligation by 30% in the CA1, by 27% in the CA3, by 26% in the dentate gyrus, and by 17% in the striatum compared with values from the contralateral hemisphere. In 10 littermates that received 1 mg/kg of the neuroprotective noncompetitive N-methyl-D-aspartate antagonist MK-801 immediately before hypoxic exposure, the regional distribution of 3 H-TCP binding in hypoxic-ischemic brain was relatively preserved and there were no interhemispheric asymmetries in 3 H-TCP binding densities. In addition, in three unoperated rats decapitated 24 hours after MK-801 treatment, 3 H-TCP binding was reduced by 15-35%; similar bilateral suppression of 3 H-TCP binding was detected in MK-801-treated ligates. Our data indicate that 3 H-TCP autoradiography can be used to assay the efficacy of neuroprotective agents in this experimental model of perinatal stroke

Influences of MCrAlY coatings on oxidation resistance of single crystal superalloy DD98M and their inter-diffusion behaviors

Energy Technology Data Exchange (ETDEWEB)

Shi, Long [School of Materials and Metallurgy, Northeastern University, Shenyang 110819 (China); Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Xin, Li, E-mail: xli@imr.ac.cn [Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Wang, Xinyue; Wang, Xiaolan; Wei, Hua; Zhu, Shenglong; Wang, Fuhui [Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

2015-11-15

Oxidation and interdiffusion behaviors of Ni-based single crystal superalloy DD98M with nominal compositions Ni–5.0Co–6.0Cr–6.3Al–6.0W–2.0Mo–6.0Ta–1.0Ti (in wt.%) and two types of MCrAlY coatings at 1000 °C and 1050 °C were investigated. Complex oxides formed on the surface of DD98M alloy when oxidized at 1000 °C and 1050 °C, which stratified, cracked and spalled. The faceted-like AlN and the particle-like and strip-like TiN formed in the alloy. The application of the NiCrAlY and NiCoCrAlYHfSi coatings greatly improved the oxidation resistance of DD98M alloy. After 500 h oxidation, α-Al{sub 2}O{sub 3} was still the dominate phase in the oxide scales formed on the coated specimens. The adhesion of the oxide scale on the NiCoCrAlYHfSi coating was much better than that on the NiCrAlY coating. Interdiffusion occurred between the coatings and the substrate, which led to the formation of the IDZ and SRZ. The IDZ of the NiCrAlY coated specimen was composed of γ phase and Al- and Ta-rich γ′ phase. The γ′ phase in the IDZ accommodated most of the inward diffusing aluminum, so the SRZ formation was suppressed when oxidized at 1050 °C. However the formation of SRZ with μ-TCP still occurred when oxidized at 1000 °C probably due to the low solubility and slow diffusion rate of the alloying elements at lower temperature. The IDZ of the NiCoCrAlYHfSi coated specimen was a single γ phase. A large amount of μ-TCP precipitated in the SRZ of the NiCoCrAlYHfSi coated specimen when oxidized at 1000 °C and 1050 °C. It can be concluded coating composition has a significant effect on the development of the IDZ and SRZ. Thermal exposure temperature also has influences on the formation of the SRZ. The mechanism of SRZ formation and TCP precipitation are discussed. - Graphical abstract: The TEM micrograph of the IDZ and SRZ of the NiCoCrAlYHfSi-coated specimen oxidized at 1050 °C for 100 h and the respective diffraction patterns of the needle-like and the

Physicomechanical, In Vitro and In Vivo Performance of 3D Printed Doped Tricalcium Phosphate Scaffolds for Bone Tissue Engineering and Drug Delivery

Science.gov (United States)

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

Bioremediation of soils co-contaminated with heavy metals and 2,4,5-trichlorophenol by fruiting body of Clitocybe maxima.

Science.gov (United States)

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.

Mesoporous bioactive glass nanolayer-functionalized 3D-printed scaffolds for accelerating osteogenesis and angiogenesis

Science.gov (United States)

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

SU-D-204-07: Retrospective Correlation of Dose Accuracy with Regions of Local Failure for Early Stage Lung Cancer Patients Treated with Stereotactic Body Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Devpura, S; Li, H; Liu, C; Fraser, C; Ajlouni, M; Movsas, B; Chetty, I [Henry Ford Health System, Detroit, MI (United States)

2016-06-15

Purpose: To correlate dose distributions computed using six algorithms for recurrent early stage non-small cell lung cancer (NSCLC) patients treated with stereotactic body radiotherapy (SBRT), with outcome (local failure). Methods: Of 270 NSCLC patients treated with 12Gyx4, 20 were found to have local recurrence prior to the 2-year time point. These patients were originally planned with 1-D pencil beam (1-D PB) algorithm. 4D imaging was performed to manage tumor motion. Regions of local failures were determined from follow-up PET-CT scans. Follow-up CT images were rigidly fused to the planning CT (pCT), and recurrent tumor volumes (Vrecur) were mapped to the pCT. Dose was recomputed, retrospectively, using five algorithms: 3-D PB, collapsed cone convolution (CCC), anisotropic analytical algorithm (AAA), AcurosXB, and Monte Carlo (MC). Tumor control probability (TCP) was computed using the Marsden model (1,2). Patterns of failure were classified as central, in-field, marginal, and distant for Vrecur ≥95% of prescribed dose, 95–80%, 80–20%, and ≤20%, respectively (3). Results: Average PTV D95 (dose covering 95% of the PTV) for 3-D PB, CCC, AAA, AcurosXB, and MC relative to 1-D PB were 95.3±2.1%, 84.1±7.5%, 84.9±5.7%, 86.3±6.0%, and 85.1±7.0%, respectively. TCP values for 1-D PB, 3-D PB, CCC, AAA, AcurosXB, and MC were 98.5±1.2%, 95.7±3.0, 79.6±16.1%, 79.7±16.5%, 81.1±17.5%, and 78.1±20%, respectively. Patterns of local failures were similar for 1-D and 3D PB plans, which predicted that the majority of failures occur in centraldistal regions, with only ∼15% occurring distantly. However, with convolution/superposition and MC type algorithms, the majority of failures (65%) were predicted to be distant, consistent with the literature. Conclusion: Based on MC and convolution/superposition type algorithms, average PTV D95 and TCP were ∼15% lower than the planned 1-D PB dose calculation. Patterns of failure results suggest that MC and convolution

Synthesis of Hydroxyapatite, β-Tricalcium Phosphate and Biphasic Calcium Phosphate Particles to Act as Local Delivery Carriers of Curcumin: Loading, Release and In Vitro Studies

Directory of Open Access Journals (Sweden)

Despoina Xidaki

2018-04-01

Full Text Available The successful synthesis of hydroxyapatite (HA, β-Tricalcium phosphate (β-TCP and two biphasic mixtures (BCPs of the two was performed by means of wet precipitation. The resulting crystals were characterized and the BCP composition was analyzed and identified as 13% HA—87% TCP and 41% HA—59% TCP. All samples were treated with curcumin solutions, and the degree of curcumin loading and release was found to be proportional to the TCP content of the ceramic. No further cytotoxicity was observed upon MG-63 treatment with the curcumin-loaded ceramics. Finally, the alkaline phosphatase activity of the cells was found to increase with increasing content of TCP, which provides an encouraging proof of concept for the use of curcumin-loaded synthetic biomaterials in bone remodeling.

Osteogenesis and angiogenesis properties of dental pulp cell on novel injectable tricalcium phosphate cement by silica doped

Energy Technology Data Exchange (ETDEWEB)

Su, Ying-Fang [Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan (China); Department of Stomatology, Chung Shan Medical University Hospital, Taichung, Taiwan (China); School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Lin, Chi-Chang, E-mail: chichang31@gmail.com [Department of Anatomy, Chung Shan Medical University, Taichung City, Taiwan (China); Huang, Tsui-Hsien; Chou, Ming-Yung [Department of Stomatology, Chung Shan Medical University Hospital, Taichung, Taiwan (China); School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Yang, Jaw-Ji, E-mail: jjyang@csmu.edu.tw [Department of Chemical and Materials Engineering, Tunghai University, Taichung, Taiwan (China); Shie, Ming-You, E-mail: eviltacasi@gmail.com [Department of Anatomy, Chung Shan Medical University, Taichung City, Taiwan (China)

2014-09-01

β-Tricalcium phosphate (β-TCP) is an osteoconductive material in clinical. In this study, we have doped silica (Si) into β-TCP and enhanced its bioactive and osteostimulative properties. To check its effectiveness, a series of Si-doped with different ratios were prepared to make new bioactive and biodegradable biocomposites for bone repair. Formation of the diametral tensile strength, ions released and weight loss of cements was considered after immersion. In addition, we also examined the behavior of human dental pulp cells (hDPCs) cultured on Si-doped β-TCP cements. The results showed that setting time and injectability of the Si-doped β-TCP cements were decreased as the Si content was increased. At the end of the immersion point, weight losses of 30.1%, 36.9%, 48.1%, and 55.3% were observed for the cement doping 0%, 10%, 20%, and 30% Si into β-TCP cements, respectively. In vitro cell experiments show that the Si-rich cements promote human dental pulp cell (hDPC) proliferation and differentiation. However, when the Si-doped in the cement is more than 20%, the amount of cells and osteogenesis protein of hDPCs was stimulated by Si released from Si-doped β-TCP cements. The degradation of β-TCP and osteogenesis of Si gives a strong reason to believe that these Si-doped β-TCP cements may prove to be promising bone repair materials. - Highlights: • The higher the Si in the cement, the shorter the setting time and the higher the DTS. • Si20-doped in TCP improved cell adhesion, proliferation and differentiation. • The Si ion stimulated collagen secreted from cells. • The Si released from substrate can promote osteogenic and angiogenic.

Strength and fracture mechanism of iron reinforced tricalcium phosphate cermet fabricated by spark plasma sintering.

Science.gov (United States)

Tkachenko, Serhii; Horynová, Miroslava; Casas-Luna, Mariano; Diaz-de-la-Torre, Sebastian; Dvořák, Karel; Celko, Ladislav; Kaiser, Jozef; Montufar, Edgar B

2018-05-01

The present work studies the microstructure and mechanical performance of tricalcium phosphate (TCP) based cermet toughened by iron particles. A novelty arises by the employment of spark plasma sintering for fabrication of the cermet. Results showed partial transformation of initial alpha TCP matrix to beta phase and the absence of oxidation of iron particles, as well as a lack of chemical reaction between TCP and iron components during sintering. The values of compressive and tensile strength of TCP/Fe cermet were 3.2 and 2.5 times, respectively, greater than those of monolithic TCP. Fracture analysis revealed the simultaneous action of crack-bridging and crack-deflection microstructural toughening mechanisms under compression. In contrast, under tension the reinforcing mechanism was only crack-bridging, being the reason for smaller increment of strength. Elastic properties of the cermet better matched values reported for human cortical bone. Thereby the new TCP/Fe cermet has potential for eventual use as a material for bone fractures fixation under load-bearing conditions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Changes of Field Incurred Chlorpyrifos and Its Toxic Metabolite Residues in Rice during Food Processing from-RAC-to-Consumption

Science.gov (United States)

Zhang, Zhiyong; Jiang, Wayne W.; Jian, Qiu; Song, Wencheng; Zheng, Zuntao; Wang, Donglan; Liu, Xianjin

2015-01-01

The objectives of this study were to determine the effects of food processing on field incurred residues levels of chlorpyrifos and its metabolite 3,5,6-Trichloro-2-pyridinol (TCP) in rice. The chlorpyrifos and TCP were found to be 1.27 and 0.093 mg kg-1 in straw and 0.41 and 0.073 mg kg-1 in grain, respectively. It is observed that the sunlight for 2 hours does not decrease the chlorpyrifos and TCP residues in grain significantly. Their residues in rice were reduced by up to 50% by hulling. The cooking reduced the chlorpyrifos and TCP in rice to undetectable level (below 0.01 mg kg-1). Processing factors (PFs) of chlorpyrifos and TCP residues in rice during food processing were similar. Various factors have impacts on the fates of chlorpyrifos and TCP residues and the important steps to reduce their residues in rice were hulling and cooking. The results can contribute to assure the consumer of a safe wholesome food supply. PMID:25608031

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

Science.gov (United States)

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

2010-08-01

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

Analytic Investigation Into Effect of Population Heterogeneity on Parameter Ratio Estimates

International Nuclear Information System (INIS)

Schinkel, Colleen; Carlone, Marco; Warkentin, Brad; Fallone, B. Gino

2007-01-01

Purpose: A homogeneous tumor control probability (TCP) model has previously been used to estimate the α/β ratio for prostate cancer from clinical dose-response data. For the ratio to be meaningful, it must be assumed that parameter ratios are not sensitive to the type of tumor control model used. We investigated the validity of this assumption by deriving analytic relationships between the α/β estimates from a homogeneous TCP model, ignoring interpatient heterogeneity, and those of the corresponding heterogeneous (population-averaged) model that incorporated heterogeneity. Methods and Materials: The homogeneous and heterogeneous TCP models can both be written in terms of the geometric parameters D 50 and γ 50 . We show that the functional forms of these models are similar. This similarity was used to develop an expression relating the homogeneous and heterogeneous estimates for the α/β ratio. The expression was verified numerically by generating pseudo-data from a TCP curve with known parameters and then using the homogeneous and heterogeneous TCP models to estimate the α/β ratio for the pseudo-data. Results: When the dominant form of interpatient heterogeneity is that of radiosensitivity, the homogeneous and heterogeneous α/β estimates differ. This indicates that the presence of this heterogeneity affects the value of the α/β ratio derived from analysis of TCP curves. Conclusions: The α/β ratio estimated from clinical dose-response data is model dependent-a heterogeneous TCP model that accounts for heterogeneity in radiosensitivity will produce a greater α/β estimate than that resulting from a homogeneous TCP model

Synthesis and characterization of nanostructured powders of hydroxyapatite and of three-calcium {beta} phosphate: elaboration of two phase compositions for application in the orthopedics and traumatology; Sintese e caracterizacao de pos nanoestruturados de hidroxiapatita e de fosfato tricalcico {beta}: elaboracao de composicoes bifasicas para aplicacoes na ortopedia e traumatologia

Energy Technology Data Exchange (ETDEWEB)

Dalmonico, G.M.L.; Pinheiro, D.M.; Camargo, N.H.A.; Orzechowki, L.G.; Goncalves, A.F.; Melnik, V.; Jesus, J.; Gemelli, E. [Universidade do Estado de Santa Catarina (UDESC), Joinville, SC (Brazil). Centro de Ciencias Tecnologicas], e-mail: gidalmonico@gmail.com

2010-07-01

This paper synthesized nano structured hydroxyapatite and three calcium {beta} phosphate, for elaboration of two phase compositions of HA/TCP in the concentration in volume of 80% HA/20% TCP-{beta}, 60% HA/40% TCP-{beta} and 50% HA/50% TCP-{beta}. For phase mixing realization, the method of mechanical fragmentation by attritor mill were used. The material recovered from the process of mechanical fragmentation was dried in rotate evaporator, supplying the two phase compositions. The preliminary studies shown the obtention of nano metric powders and a good phase dispersions inside the two phase compositions. (author)

Reactions between 52100 steel and tricresyl phosphate neat and mixed with hydrocarbon oil

International Nuclear Information System (INIS)

Arezzo, F.; Moore, R.L.

1987-01-01

Some of the results from a previous study which showed reactions between iron surfaces (52100 steel) and tricresyl phosphate (TCP) dissolved in hydrocarbon oil are discussed in this paper. This study had shown that microscale oxidation of the hydrocarbon oil and preferential adsorption phenomena within the oil system components may result in a desirable phosphate type of coating. This phosphate is organic and it is converted into iron phosphate on argon ion sputtering. Also discussed in this paper are the results of a more recent work which shows the reactivity of neat TCP with an identical 52100 steel surface. The results of electron spectroscopy for chemical analysis indicate that neat TCP behaves quite differently from TCP diluted in hydrocarbon oil. The phosphate generated on the metal surface by neat TCP yields predominantly a phosphide when subjected to argon ion sputtering. (orig.)

Tricalcium Phosphate Containing Sodium Hexametaphosphate as Polymer Suspension Stabilizer

Directory of Open Access Journals (Sweden)

K. Rahbar Shamskar

2008-12-01

Full Text Available Tricalcium phosphate as hydroxyapatite is used as a suspension stabilizer in styrene polymerization process. Particle size of TCP plays an essential role in the particles’ size distribution and geometrical form of polystyrene products. As the particle size of TCP is reduced, there will be much better chance to engulf the styrene particles. The higher the number of TCP particles surrounding each styrene particle, the lesser will be their tendency to form a large particle after collision. Therefore, there will be higher percentages of spherical polystyrene with small particle size and narrower size distribution in the product. Experimental results have indicated that the addition of sodium hexametaphosphate (SHMP to the reaction mixture of lime and phosphoric acid, after drying the product by spray dryer, lead to decrease the size of TCP particles from ca. 5 μm (without SHMP to ca. 1.5 μm (with SHMP. In this study, the role of TCP containing SHMP as polymer suspension stabilizer and consequently the beads size of polystyrene is investigated in laboratory scale. The results show that despite addition of SHMP to the reaction mixture of lime and phosphoric acid decreases the TCP particles size and the mean bead size of the product of polystyrene become larger than the product prepared by TCP without SHMP.

Collagenous matrix supported by a 3D-printed scaffold for osteogenic differentiation of dental pulp cells.

Science.gov (United States)

Fahimipour, Farahnaz; Dashtimoghadam, Erfan; Rasoulianboroujeni, Morteza; Yazdimamaghani, Mostafa; Khoshroo, Kimia; Tahriri, Mohammadreza; Yadegari, Amir; Gonzalez, Jose A; Vashaee, Daryoosh; Lobner, Douglas C; Jafarzadeh Kashi, Tahereh S; Tayebi, Lobat

2018-02-01

A systematic characterization of hybrid scaffolds, fabricated based on combinatorial additive manufacturing technique and freeze-drying method, is presented as a new platform for osteoblastic differentiation of dental pulp cells (DPCs). The scaffolds were consisted of a collagenous matrix embedded in a 3D-printed beta-tricalcium phosphate (β-TCP) as the mineral phase. The developed construct design was intended to achieve mechanical robustness owing to 3D-printed β-TCP scaffold, and biologically active 3D cell culture matrix pertaining to the Collagen extracellular matrix. The β-TCP precursor formulations were investigated for their flow-ability at various temperatures, which optimized for fabrication of 3D printed scaffolds with interconnected porosity. The hybrid constructs were characterized by 3D laser scanning microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and compressive strength testing. The in vitro characterization of scaffolds revealed that the hybrid β-TCP/Collagen constructs offer superior DPCs proliferation and alkaline phosphatase (ALP) activity compared to the 3D-printed β-TCP scaffold over three weeks. Moreover, it was found that the incorporation of TCP into the Collagen matrix improves the ALP activity. The presented results converge to suggest the developed 3D-printed β-TCP/Collagen hybrid constructs as a new platform for osteoblastic differentiation of DPCs for craniomaxillofacial bone regeneration. Copyright © 2017. Published by Elsevier Ltd.

[Biological evaluation of three-dimensional printed co-poly lactic acid/glycolic acid/tri-calcium phosphate scaffold for bone reconstruction].

Science.gov (United States)

Li, S Y; Zhou, M; Lai, Y X; Geng, Y M; Cao, S S; Chen, X M

2016-11-09

Objective: To biologically evaluate the three-dimensional(3D) printed co-poly lactic acid/glycolic acid/tri-calcium phosphate(PLGA/TCP) scaffold which could be used for repairing oral and maxillofacial bone defects, and to provide experimental evidence for its further research and clinical application. Methods: PLGA/TCP scaffolds were fabricated using low temperature rapid prototyping technique. Micro-CT and scanning electron microscope(SEM) were used to characterize the surface morphology. MC3T3-E1 cells were seeded onto the scaffold and stained with the rhodamine phalloidin and calcein acetomethoxy. After that, confocal laser scanning microscope was exploited to observe the features and viability of the cells. Moreover, the cells were co-cultured with the extract of PLGA/TCP and complete medium, respectively. The proliferation capability of the cells was assessed by the cell counting kit-8 (CCK-8) on the 1st, 2nd, and 3rd day. The PLGA/TCP scaffolds incorporated with recombinant human bone morphogenetic protein-2(rhBMP-2) of 0, 30, 60 μg(i.e. blank control group, low-dose group and high-dose group) were implanted into the latissimus dorsi muscle of the rats, and 6 weeks later, the samples were harvested to estimate the volume and pattern of new bone. Results: The 3D printed PLGA/TCP scaffold possessed a regular and well-defined porous stereo-structure with porosity of (73±3)%. Micro-CT and SEM showed that pore size were (379±32) and (453±29) μm respectively, and distance between layers were (452± 24) and (415±25) μm, and cylinder diameter were (342±24) and (350±28) μm. It also exhibited excellent cell adhesion and growth ability on the exterior and inner surface through rhodamine phalloidin and calcein acetomethoxy staining. The CCK-8 test demonstrated that the absorbance value of extract group on the 1st and 2nd day(0.51±0.08 and 0.63±0.09) were significantly higher than those in the blank control group(0.39± 0.05 and 0.53±0.05)( P 0.05) on the 3

The Use of Post-Purchase Communication to Reduce Dissonance and Improve Direct Marketing Effectiveness.

Science.gov (United States)

Milliman, Ronald E.; Decker, Phillip J.

1990-01-01

Demonstrates the use and potentially positive effects of postpurchase communication on order refund requests and reorder rates. Finds that dissonance was effectively reduced through postpurchase communication. (MG)

Using calcium silicate to regulate the physicochemical and biological properties when using β-tricalcium phosphate as bone cement

Energy Technology Data Exchange (ETDEWEB)

Kao, Chia-Tze; Huang, Tsui-Hsien [School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Chen, Yi-Jyun [School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Dental Department, Taichung Hospital, Ministry of Health and Welfare, Taichung City, Taiwan (China); Hung, Chi-Jr [School of Dentistry, Chung Shan Medical University, Taichung, Taiwan (China); Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Lin, Chi-Chang, E-mail: chichang31@gmail.com [Department of Chemical and Materials Engineering, Tunghai University, Taichung, Taiwan (China); Shie, Ming-You, E-mail: eviltacasi@gmail.com [Department of Chemical and Materials Engineering, Tunghai University, Taichung, Taiwan (China)

2014-10-01

β-Tricalcium phosphate (β-TCP) is an osteoconductive material. For this research we have combined it with a low degradation calcium silicate (CS) to enhance its bioactive and osteostimulative properties. To check its effectiveness, a series of β-TCP/CS composites with different ratios were prepared to make new bioactive and biodegradable biocomposites for bone repair. Regarding the formation of bone-like apatite, the diametral tensile strength as well as the ion release and weight loss of composites were compared both before and after immersions in simulated body fluid (SBF). In addition, we also examined the behavior of human dental pulp cells (hDPCs) cultured on β-TCP/CS composites. The results show that the apatite deposition ability of the β-TCP/CS composites improves as the CS content is increased. For composites with more than a 60% CS content, the samples become completely covered by a dense bone-like apatite layer. At the end of the immersion period, weight losses of 24%, 32%, 34%, 38%, 41%, and 45% were observed for the composites containing 0%, 20%, 40%, 80%, 80% and 100% β-TCP cements, respectively. In addition, the antibacterial activity of CS/β-TCP composite improves as the CS-content is increased. In vitro cell experiments show that the CS-rich composites promote human dental pulp cell (hDPC) proliferation and differentiation. However, when the CS quantity in the composite is less than 60%, the quantity of cells and osteogenesis protein of hDPCs is stimulated by Si released from the β-TCP/CS composites. The degradation of β-TCP and the osteogenesis of CS give strong reason to believe that these calcium-based composite cements will prove to be effective bone repair materials. - Highlights: • CS improved the physicochemical properties and osteogenic activity of β-TCP. • Higher CS in the composite, the shorter setting time and the higher DTS was found. • With a CS more than 40%, the osteogenesis and angiogenesis proteins were promoted by

The effects of Ca2SiO4–Ca3(PO4)2 ceramics on adult human mesenchymal stem cell viability, adhesion, proliferation, differentiation and function

International Nuclear Information System (INIS)

De Aza, Piedad N.; García-Bernal, David; Cragnolini, Francesca; Velasquez, Pablo; Meseguer-Olmo, Luis

2013-01-01

Bioceramic samples with osteogenic properties, suitable for use in the regeneration of hard tissue, were synthesized. The materials consisting of α-tricalcium phosphate (αTCP) and also αTCP doped with either 1.5 wt.% or 3.0 wt.% of dicalcium silicate (C 2 S) in the system Dicalcium Silicate–Tricalcium Phosphate (C 2 S–TCP) were obtained by solid state reaction. All materials were composed of a single phase, αTCP in the case of a pure material, or solid solution of C 2 S in αTCP (αTCPss) for the doped αTCP. Viability, proliferation and in vitro osteoinductive capacity were investigated by seeding, adult mesenchymal stem cells of human origin (ahMSCs) which were CD73 + , CD90 + , CD105 + , CD34 − and CD45 − onto the 3 substrates for 30 days. Results show a non-cytotoxic effect after applying an indirect apoptosis test (Annexin V/7-AAD staining), so ahMSCs adhered, spread, proliferated and produced extracellular matrix (Heparan-sulfate proteoglycan (HS) and osteopontin (OP)) on all the ceramics studied. Finally, the cells lost the cluster differentiation marker expression CD73, CD90 y CD105 characteristic of ahMSCs and they showed an osteoblastic phenotype (Alkaline phosphatase activity (ALP), Osteocalcin production (OC), Collagen type I expression (Col-I), and production of mineralization nodules on the extracellular matrix). These observations were more evident in the αTCP ceramic doped with 1.5 wt.% C 2 S, indicating osteoblastic differentiation as a result of the increased concentration of solid solution of C 2 S in αTCP (αTCPss). Overall, these results suggest that the ceramics studied are cytocompatible and they are able to induce osteoblastic differentiation of undifferentiated ahMSCs. - Highlights: • The ceramics studied are cytocompatible and show osteoinductive properties. • Results show a non-cytotoxic effect after applying an indirect apoptosis test. • ahMSCs adhered, spread, proliferated and produced extracellular matrix. • ah

A prospective, randomized pilot study on the safety and efficacy of recombinant human growth and differentiation factor-5 coated onto β-tricalcium phosphate for sinus lift augmentation.

Science.gov (United States)

Koch, Felix P; Becker, Jürgen; Terheyden, Hendrik; Capsius, Björn; Wagner, Wilfried

2010-11-01

The aim of this prospective, randomized clinical trial was to investigate the potential of recombinant human growth and differentiation factor-5 (rhGDF-5) coated onto β-tricalcium phosphate (β-TCP) (rhGDF-5/β-TCP) to support bone formation after sinus lift augmentation. In total, 31 patients participated in this multicenter clinical trial. They required a two-stage unilateral maxillary sinus floor augmentation (residual bone height augmentation with rhGDF-5/β-TCP and a 3-month healing period, (b) augmentation with rhGDF-5/β-TCP and a 4-month healing period and (c) medical device β-TCP mixed with autologous bone and a 4-month healing period. The primary study objective was the area of newly formed bone within the augmented area as assessed by histomorphometric evaluation of trephine bur biopsies. The osseous regeneration was similar in each treatment group; the amount of newly formed bone ranged between 28% (± 15.5%) and 31.8% (± 17.9%). Detailed analysis of histological data will be published elsewhere. As secondary efficacy variables, the augmentation height at the surgery site was measured by radiography. The largest augmentation was radiologically achieved in the rhGDF-5/β-TCP - 3-month and the rhGDF-5/β-TCP - 4-month treatment groups. As safety parameters, adverse events were recorded and anti-drug antibody levels were evaluated. Most of the adverse events were judged as unrelated to the study medication. Four out of 47 (8.5%) implants failed in patients treated with rhGDF-5/β-TCP, a result that is in agreement with the general implant failure rate of 5-15%. Transiently very low amounts of anti-rhGDF-5 antibodies were detected in some patients who received rhGDF-5, which was not related to the bone formation outcome. rhGDF-5/β-TCP was found to be effective and safe as the control treatment with autologous bone mixed β-TCP in sinus floor augmentation. Thus, further investigation regarding efficacy and safety will be carried out in larger patient

The effects of Ca{sub 2}SiO{sub 4}–Ca{sub 3}(PO{sub 4}){sub 2} ceramics on adult human mesenchymal stem cell viability, adhesion, proliferation, differentiation and function

Energy Technology Data Exchange (ETDEWEB)

De Aza, Piedad N., E-mail: piedad@umh.es [Instituto de Bioingeniería, Universidad Miguel Hernández, Avda. Universidad s/n, 03202 Elche, Alicante (Spain); García-Bernal, David, E-mail: redond@gmail.com [Centro Integrado de Investigación Biomédica (CEIB), Universidad de Murcia, 30120 Murcia (Spain); Cragnolini, Francesca, E-mail: dott.ssa_franci@hotmail.it [Centro Integrado de Investigación Biomédica (CEIB), Universidad de Murcia, 30120 Murcia (Spain); Velasquez, Pablo, E-mail: pvlasquez@umh.es [Instituto de Bioingeniería, Universidad Miguel Hernández, Avda. Universidad s/n, 03202 Elche, Alicante (Spain); Meseguer-Olmo, Luis, E-mail: lmeseguer.doc@gmail.com [Centro Integrado de Investigación Biomédica (CEIB), Universidad de Murcia, 30120 Murcia (Spain); Unidad de Bioingeniería ósea, Servicio de Cirugía Ortopédica, Hospital Universitario Virgen de la Arrixaca, Universidad de Murcia, 30120 Murcia (Spain)

2013-10-15

Bioceramic samples with osteogenic properties, suitable for use in the regeneration of hard tissue, were synthesized. The materials consisting of α-tricalcium phosphate (αTCP) and also αTCP doped with either 1.5 wt.% or 3.0 wt.% of dicalcium silicate (C{sub 2}S) in the system Dicalcium Silicate–Tricalcium Phosphate (C{sub 2}S–TCP) were obtained by solid state reaction. All materials were composed of a single phase, αTCP in the case of a pure material, or solid solution of C{sub 2}S in αTCP (αTCPss) for the doped αTCP. Viability, proliferation and in vitro osteoinductive capacity were investigated by seeding, adult mesenchymal stem cells of human origin (ahMSCs) which were CD73{sup +}, CD90{sup +}, CD105{sup +}, CD34{sup −} and CD45{sup −} onto the 3 substrates for 30 days. Results show a non-cytotoxic effect after applying an indirect apoptosis test (Annexin V/7-AAD staining), so ahMSCs adhered, spread, proliferated and produced extracellular matrix (Heparan-sulfate proteoglycan (HS) and osteopontin (OP)) on all the ceramics studied. Finally, the cells lost the cluster differentiation marker expression CD73, CD90 y CD105 characteristic of ahMSCs and they showed an osteoblastic phenotype (Alkaline phosphatase activity (ALP), Osteocalcin production (OC), Collagen type I expression (Col-I), and production of mineralization nodules on the extracellular matrix). These observations were more evident in the αTCP ceramic doped with 1.5 wt.% C{sub 2}S, indicating osteoblastic differentiation as a result of the increased concentration of solid solution of C{sub 2}S in αTCP (αTCPss). Overall, these results suggest that the ceramics studied are cytocompatible and they are able to induce osteoblastic differentiation of undifferentiated ahMSCs. - Highlights: • The ceramics studied are cytocompatible and show osteoinductive properties. • Results show a non-cytotoxic effect after applying an indirect apoptosis test. • ahMSCs adhered, spread, proliferated

A new iron calcium phosphate material to improve the osteoconductive properties of a biodegradable ceramic: a study in rabbit calvaria.

Science.gov (United States)

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.

Disposition of 1,2,3-trichloropropane in the Fischer 344 rat: conventional and physiological pharmacokinetics

International Nuclear Information System (INIS)

Volp, R.F.; Sipes, I.G.; Falcoz, C.; Carter, D.E.; Gross, J.F.

1984-01-01

To investigate the disposition of 1,2,3-trichloropropane (TCP), [14C]-TCP was administered iv to male Fischer 344 rats. Unchanged TCP and total radiolabel were determined in tissues and excreta at varying intervals after administration. The compound was distributed and eliminated rapidly. Initial and terminal half-lives of unchanged TCP in the blood were 0.29 and 23 hr. Adipose tissue accumulated 37% of the dose within 15 min and retained more of the dose than any other tissue until 4 hr; most (69%) of the radiolabel in adipose tissue through 4 hr was unchanged TCP. After 4 hr, the liver contained the largest fraction of the dose, primarily as metabolites. Thus TCP disappeared from adipose tissue while metabolites appeared in liver and other tissues. Excretion was nearly complete (90% of the dose) in 24 hr and was predominantly via the urine (47% of the dose). Expiration was the only route by which unchanged TCP (5% of the dose) was excreted. In addition, 25% of the dose was expired as carbon dioxide. There were numerous other metabolites, none accounting for more than 10% of the dose. Nonvolatile metabolites were longer lived than the parent compound. On the basis of high water solubility, reaction with 2,4-dinitrofluorobenzene, and diminished radiolabel in bile of glycidol-treated rats, glutathione conjugation is suggested as an important metabolic route for TCP. A physiological pharmacokinetic model was developed to describe the time course of trichloropropane concentration in tissues. The model demonstrates the possibility of using physiological and pharmacokinetic data to predict concentration-time relations for toxic compounds

Suppression of Virulence of Toxigenic Vibrio cholerae by Anethole through the Cyclic AMP (cAMP-cAMP Receptor Protein Signaling System.

Directory of Open Access Journals (Sweden)

M Shamim Hasan Zahid

Full Text Available Use of natural compounds as antivirulence drugs could be an alternative therapeutic approach to modify the outcome of bacterial infections, particularly in view of growing resistance to available antimicrobials. Here, we show that sub-bactericidal concentration of anethole, a component of sweet fennel seed, could suppress virulence potential in O1 El Tor biotype strains of toxigenic Vibrio cholerae, the causative agent of the ongoing 7th cholera pandemic. The expression of cholera toxin (CT and toxin coregulated pilus (TCP, the major virulence factors of V. cholerae, is controlled through a regulatory cascade involving activation of ToxT with synergistic coupling interaction of ToxR/ToxS with TcpP/TcpH. We present evidence that anethole inhibits in vitro expression of CT and TCP in a toxT-dependent but toxR/toxS-independent manner and through repression of tcpP/tcpH, by using bead-ELISA, western blotting and quantitative real-time RT-PCR assays. The cyclic AMP (cAMP-cAMP receptor protein (CRP is a well-studied global signaling system in bacterial pathogens, and this complex is known to suppress expression of tcpP/tcpH in V. cholerae. We find that anethole influences the virulence regulatory cascade by over-expressing cyaA and crp genes. Moreover, suppression of toxigenic V. cholerae-mediated fluid accumulation in ligated ileum of rabbit by anethole demonstrates its potentiality as an antivirulence drug candidate against the diseases caused by toxigenic V. cholerae. Taken altogether, these results revealing a mechanism of virulence inhibition in V. cholerae by the natural compound anethole, may have relevance in designing antivirulence compounds, particularly against multiple antibiotic resistant bacterial pathogens.

Degradation of 2,4,6-trichlorophenol with peroxymonosulfate catalyzed by soluble and supported iron porphyrins

International Nuclear Information System (INIS)

Günay, Tuğçe; Çimen, Yasemin

2017-01-01

Degradation of 2,4,6-trichloropenol (TCP) with peroxymonosulfate (PMS) catalyzed by iron porphyrin tetrasulfonate ([FePTS)] was investigated in an 8-to-1 (v/v) CH 3 OH-H 2 O mixture. Typical reaction medium contained a 4.00 mL methanol solution of TCP (0.100 mmol), a 0.50 mL aqueous solution of catalyst (5.0 × 10 −4  mmol), and 0.100 mmol PMS (as 0.031 g of Oxone). The reaction was performed at ambient temperature. The conversion of TCP was 74% in 30 min and 80% in 6 h when the catalyst was [FePTS]. Amberlite IRA-900 supported [FePTS] catalyst was also prepared. In the recycling experiments the homogeneous [FePTS] lost its activity after the first cycle, while [FePTS]-Amberlite IRA 900 maintained its activity for the first 2 cycles. After the second cycle, the conversion of TCP dropped to <10% for Amberlite IRA-900 supported [FePTS] catalyst. The degradation of TCP with PMS was also attempted using cobalt, copper, nickel and palladium porphyrin tetrasulfonate catalysts, however, no catalytic activity was observed with these structures. - Highlights: • The method presents an effective oxidation of TCP. • This research provided persistence, less harmful, self-degradable and more environmental oxidation products. • About seventy percent conversions of TCP in 30 min was achieved at room temperature. - This research provided non-persistent, less harmful, self-degradable and more environmentally friendly oxidation products. About 70% conversions of TCP in 30 min was achieved at room temperature.

Suppression of Virulence of Toxigenic Vibrio cholerae by Anethole through the Cyclic AMP (cAMP)-cAMP Receptor Protein Signaling System.

Science.gov (United States)

Zahid, M Shamim Hasan; Awasthi, Sharda Prasad; Asakura, Masahiro; Chatterjee, Shruti; Hinenoya, Atsushi; Faruque, Shah M; Yamasaki, Shinji

2015-01-01

Use of natural compounds as antivirulence drugs could be an alternative therapeutic approach to modify the outcome of bacterial infections, particularly in view of growing resistance to available antimicrobials. Here, we show that sub-bactericidal concentration of anethole, a component of sweet fennel seed, could suppress virulence potential in O1 El Tor biotype strains of toxigenic Vibrio cholerae, the causative agent of the ongoing 7th cholera pandemic. The expression of cholera toxin (CT) and toxin coregulated pilus (TCP), the major virulence factors of V. cholerae, is controlled through a regulatory cascade involving activation of ToxT with synergistic coupling interaction of ToxR/ToxS with TcpP/TcpH. We present evidence that anethole inhibits in vitro expression of CT and TCP in a toxT-dependent but toxR/toxS-independent manner and through repression of tcpP/tcpH, by using bead-ELISA, western blotting and quantitative real-time RT-PCR assays. The cyclic AMP (cAMP)-cAMP receptor protein (CRP) is a well-studied global signaling system in bacterial pathogens, and this complex is known to suppress expression of tcpP/tcpH in V. cholerae. We find that anethole influences the virulence regulatory cascade by over-expressing cyaA and crp genes. Moreover, suppression of toxigenic V. cholerae-mediated fluid accumulation in ligated ileum of rabbit by anethole demonstrates its potentiality as an antivirulence drug candidate against the diseases caused by toxigenic V. cholerae. Taken altogether, these results revealing a mechanism of virulence inhibition in V. cholerae by the natural compound anethole, may have relevance in designing antivirulence compounds, particularly against multiple antibiotic resistant bacterial pathogens.

Pattern optimizing verification of self-align quadruple patterning

Science.gov (United States)

Yamato, Masatoshi; Yamada, Kazuki; Oyama, Kenichi; Hara, Arisa; Natori, Sakurako; Yamauchi, Shouhei; Koike, Kyohei; Yaegashi, Hidetami

2017-03-01

Lithographic scaling continues to advance by extending the life of 193nm immersion technology, and spacer-type multi-patterning is undeniably the driving force behind this trend. Multi-patterning techniques such as self-aligned double patterning (SADP) and self-aligned quadruple patterning (SAQP) have come to be used in memory devices, and they have also been adopted in logic devices to create constituent patterns in the formation of 1D layout designs. Multi-patterning has consequently become an indispensible technology in the fabrication of all advanced devices. In general, items that must be managed when using multi-patterning include critical dimension uniformity (CDU), line edge roughness (LER), and line width roughness (LWR). Recently, moreover, there has been increasing focus on judging and managing pattern resolution performance from a more detailed perspective and on making a right/wrong judgment from the perspective of edge placement error (EPE). To begin with, pattern resolution performance in spacer-type multi-patterning is affected by the process accuracy of the core (mandrel) pattern. Improving the controllability of CD and LER of the mandrel is most important, and to reduce LER, an appropriate smoothing technique should be carefully selected. In addition, the atomic layer deposition (ALD) technique is generally used to meet the need for high accuracy in forming the spacer film. Advances in scaling are accompanied by stricter requirements in the controllability of fine processing. In this paper, we first describe our efforts in improving controllability by selecting the most appropriate materials for the mandrel pattern and spacer film. Then, based on the materials selected, we present experimental results on a technique for improving etching selectivity.

Specialization Patterns

DEFF Research Database (Denmark)

Schultz, Ulrik Pagh; Lawall, Julia Laetitia; Consel, Charles

2000-01-01

Design patterns offer many advantages for software development, but can introduce inefficiency into the final program. Program specialization can eliminate such overheads, but is most effective when targeted by the user to specific bottlenecks. Consequently, we propose that these concepts...... are complementary. Program specialization can optimize programs written using design patterns, and design patterns provide information about the program structure that can guide specialization. Concretely, we propose specialization patterns, which describe how to apply program specialization to optimize uses...... of design patterns. In this paper, we analyze the specialization opportunities provided by specific uses of design patterns. Based on the analysis of each design pattern, we define the associated specialization pattern. These specialization opportunities can be declared using the specialization classes...

Comparison of TEAR and TFRC throughput for Drop tail and RED Queue Management Techniques

Directory of Open Access Journals (Sweden)

Parminderjeet Singh

2014-12-01

Full Text Available The comparison of throughput for TEAR (TCP emulation at receivers and TFRC TCP friendly rate control in MANETs is done with varying Active queue Management Techniques. The analysis reveals that for bandwidth constraint links, TEAR and TFRC perform far better than normal traffic propagation through TCP. In case of TEAR, the processing and route congestion algorithm load is shared by the receiver resulting in lesser load at the transmitters. In TFRC the TCP traffic is propagated via an algorithm to curb acknowledgement congestions. The effect of these two techniques is monitored on Droptail and RED, two of the most common Active Queue Management Techniques.

Reordering of Nuclear Quantum States in Rare Isotopes

Science.gov (United States)

Flanagan, Kieran

2010-02-01

A key question in modern nuclear physics relates to the ordering of quantum states, and whether the predictions made by the shell model hold true far from stability. Recent innovations in technology and techniques at radioactive beam facilities have allowed access to rare isotopes previously inaccessible to experimentalists. Measurements that have been performed in several regions of the nuclear chart have yielded surprising and dramatic changes in nuclear structure, where level ordering is quite different than expected from previous theoretical descriptions. In order to reconcile the difference between experiment and theory, new shell-model interactions have been proposed, which include the role of the tensor force as part of the monopole term from the expansion of the residual proton-neutron interaction. This has motivated a series of laser spectroscopy experiments that have studied the neutron-rich copper and gallium isotopes at the ISOLDE facility. This work has deduced without nuclear-model dependence the spin, moments and charge radii. The results of this work and their implications for nuclear structure near ^78Ni will be discussed. )

Designing a place called home reordering the suburbs

CERN Document Server

Wentling, James

2017-01-01

This insightful volume shares design ideas to help builders, planners and architects create mass-produced affordable housing that pushes suburban development in more sustainable, liveable directions. The author argues that improving the quality of design in our new homes and communities for greater resiliency, sustainability, and equality, we can build neighborhoods and communities where residents feel more connected t their homes and to one another. Through text, photographs and illustrations, the book reviews prototypical American housing design, then suggest ways to both learn from the past as well as adapt for new environmental imperatives, demographic changes and lifestyle needs. Written by a practicing architect with 25+ years of experience optimizing residential design, this pioneering approach to suburban building will inspire readers to view mass produced housing through a new, modern lens.

Bandwidth Management in Resource Constrained Networks

Science.gov (United States)

2012-03-01

Postgraduate School OSI Open Systems Interconnection QoS Quality of Service TCP Transmission Control Protocol/Internet Protocol TCP/IP Transmission...filtering. B. NORMAL TCP/IP COMMUNICATIONS The Internet is a “complex network WAN that connects LANs and clients around the globe” (Dean, 2009...of the Open Systems Interconnection ( OSI ) model allowing them to route traffic based on MAC address (Kurose & Ross, 2009). While switching

SU-E-T-352: Why Is the Survival Rate Low in Oropharyngeal Squamous Cell Carcinoma?

Energy Technology Data Exchange (ETDEWEB)

Huang, Z; Feng, Y; Rasmussen, K; Rice, J; Stephenson, S; Ferreira, Maria C [East Carolina University, Greenville, NC (United States); Liu, T [Baylor College of Medicine, Houston, TX (United States); Yuh, K [California Institute of Technology, Pasadena, CA (United States); Wang, R; Grecula, J [Case Western Reserve University, Cleveland, OH (United States); Lo, S [The Ohio State University, Columbus, OH (United States); Mayr, N; Yuh, W [University of Washington, Seattle, WA (United States)

2014-06-01

Purpose: Tumors are composed of a large number of clonogens that have the capability of indefinite reproduction. Even when there is complete clinical or radiographic regression of the gross tumor mass after treatment, tumor recurrence can occur if the clonogens are not completely eradicated by radiotherapy. This study was to investigate the colonogen number and its association with the tumor control probability (TCP) in oropharyngeal squamous cell carcinoma (OSCCA). Methods: A literature search was conducted to collect clinical information of patients with OSCCA, including the prescription dose, tumor volume and survival rate. The linear-quadratic (LQ) model was incorporated into TCP model for clinical data analysis. The total dose ranged from 60 to 70 Gy and tumor volume ranged from 10 to 50 cc. The TCP was calculated for each group according to tumor size and dose. The least χ{sup 2} method was used to fit the TCP calculation to clinical data while other LQ model parameters (α, β) were adopted from the literature, due to the limited patient data. Results: A total of 190 patients with T2–T4 OSCCA were included. The association with HPV was not available for all the patients. The 3-year survival rate was about 82% for T2 squamous cell carcinoma and 40% for advanced tumors. Fitting the TCP model to the survival data, the average clonogen number was 1.56×10{sup 12}. For the prescription dose of 70 Gy, the calculated TCP ranged from 40% to 90% when the tumor volume varied from 10 to 50 cc. Conclusion: Our data suggests variation between the clonogen number and TCP in OSCCA. Tumors with larger colonogen number tend to have lower TCP and therefore dose escalation above 70 Gy may be indicated in order to improve the TCP and survival rate. Our result will require future confirmation with a large number of patients.

A bistable switch and anatomical site control Vibrio cholerae virulence gene expression in the intestine.

Directory of Open Access Journals (Sweden)

Alex T Nielsen

2010-09-01

Full Text Available A fundamental, but unanswered question in host-pathogen interactions is the timing, localization and population distribution of virulence gene expression during infection. Here, microarray and in situ single cell expression methods were used to study Vibrio cholerae growth and virulence gene expression during infection of the rabbit ligated ileal loop model of cholera. Genes encoding the toxin-coregulated pilus (TCP and cholera toxin (CT were powerfully expressed early in the infectious process in bacteria adjacent to epithelial surfaces. Increased growth was found to co-localize with virulence gene expression. Significant heterogeneity in the expression of tcpA, the repeating subunit of TCP, was observed late in the infectious process. The expression of tcpA, studied in single cells in a homogeneous medium, demonstrated unimodal induction of tcpA after addition of bicarbonate, a chemical inducer of virulence gene expression. Striking bifurcation of the population occurred during entry into stationary phase: one subpopulation continued to express tcpA, whereas the expression declined in the other subpopulation. ctxA, encoding the A subunit of CT, and toxT, encoding the proximal master regulator of virulence gene expression also exhibited the bifurcation phenotype. The bifurcation phenotype was found to be reversible, epigenetic and to persist after removal of bicarbonate, features consistent with bistable switches. The bistable switch requires the positive-feedback circuit controlling ToxT expression and formation of the CRP-cAMP complex during entry into stationary phase. Key features of this bistable switch also were demonstrated in vivo, where striking heterogeneity in tcpA expression was observed in luminal fluid in later stages of the infection. When this fluid was diluted into artificial seawater, bacterial aggregates continued to express tcpA for prolonged periods of time. The bistable control of virulence gene expression points to a

Regulation of physicochemical properties, osteogenesis activity, and fibroblast growth factor-2 release ability of β-tricalcium phosphate for bone cement by calcium silicate

International Nuclear Information System (INIS)

Su, Ching-Chuan; Kao, Chia-Tze; Hung, Chi-Jr; Chen, Yi-Jyun; Huang, Tsui-Hsien; Shie, Ming-You

2014-01-01

β-Tricalcium phosphate (β-TCP) is an osteoconductive material. For this research we have combined it with a low degradation calcium silicate (CS) to enhance its bioactive and osteostimulative properties. To check its effectiveness, a series of β-TCP/CS composites with different ratios were prepared to make new bioactive and biodegradable biocomposites for bone repair. Formation of bone-like apatite, the diametral tensile strength, and weight loss of composites were considered before and after immersion in simulated body fluid (SBF). In addition, we also examined the effects of fibroblast growth factor-2 (FGF-2) released from β-TCP/CS composites and in vitro human dental pulp cell (hDPC) and studied its behavior. The results showed that the apatite deposition ability of the β-TCP/CS composites was enhanced as the CS content was increased. For composites with more than 50% CS contents, the samples were completely covered by a dense bone-like apatite layer. At the end of the immersion point, weight losses of 19%, 24%, 33%, 42%, and 51% were observed for the composites containing 0%, 30%, 50%, 70% and 100% β-TCP cements, respectively. In vitro cell experiments show that the CS-rich composites promote human dental pulp cell (hDPC) proliferation and differentiation. However, when the CS quantity in the composite is less than 70%, the amount of cells and osteogenesis protein of hDPCs was stimulated by FGF-2 released from β-TCP/CS composites. The combination of FGF-2 in degradation of β-TCP and osteogenesis of CS gives a strong reason to believe that these calcium-based composite cements may prove to be promising bone repair materials. - Highlights: • CS improved physicochemical properties and osteogenic activity of β-TCP. • The higher the CS in the cement, the shorter the setting time and the higher the DTS. • The cell behavior was stimulated by FGF-2 released from composite containing 50% CS. • β-TCP/CS composite with FGF-2 has optimal properties for

AO–MW–PLS method applied to rapid quantification of teicoplanin with near-infrared spectroscopy

Directory of Open Access Journals (Sweden)

Jiemei Chen

2017-01-01

Full Text Available Teicoplanin (TCP is an important lipoglycopeptide antibiotic produced by fermenting Actinoplanes teichomyceticus. The change in TCP concentration is important to measure in the fermentation process. In this study, a reagent-free and rapid quantification method for TCP in the TCP–Tris–HCl mixture samples was developed using near-infrared (NIR spectroscopy by focusing our attention on the fermentation process for TCP. The absorbance optimization (AO partial least squares (PLS was proposed and integrated with the moving window (MW PLS, which is called AO–MW–PLS method, to select appropriate wavebands. A model set that includes various wavebands that were equivalent to the optimal AO–MW–PLS waveband was proposed based on statistical considerations. The public region of all equivalent wavebands was just one of the equivalent wavebands. The obtained public regions were 1540–1868nm for TCP and 1114–1310nm for Tris. The root-mean-square error and correlation coefficient for leave-one-out cross validation were 0.046mg mL−1 and 0.9998mg mL−1 for TCP, and 0.235mg mL−1 and 0.9986mg mL−1 for Tris, respectively. All the models achieved highly accurate prediction effects, and the selected wavebands provided valuable references for designing specialized spectrometers. This study provided a valuable reference for further application of the proposed methods to TCP fermentation broth and to other spectroscopic analysis fields.

Can macrocirculation changes predict nonhealing diabetic foot ulcers?

Science.gov (United States)

Lee, Ye-Na; Kim, Hyon-Surk; Kang, Jeong-A; Han, Seung-Kyu

2014-01-01

Transcutaneous partial oxygen tension (TcpO2) is considered the gold standard for assessment of tissue oxygenation, which is an essential factor for wound healing. The purpose of this study was to evaluate the association between macrocirculation and TcpO2 in persons with diabetes mellitus. Ninety-eight patients with diabetic foot ulcers participated in the study (61 men and 37 women). The subjects had a mean age of 66.6 years (range, 30-83 years) and were treated at the Diabetic Wound Center of Korea University Guro Hospital, Seoul, Republic of Korea. Macrocirculation was evaluated using 2 techniques: computed tomographic angiography and Doppler ultrasound. Macrocirculation scores were based on the patency of the two tibial arteries in 98 patients. Computed tomographic angiography and Doppler ultrasound scores (0-4 points) were given according to intraluminal filling defects and arterial pulse waveform of each vessel, respectively. Tissue oxygenation was measured by TcpO2. Macrocirculation scores were statistically analyzed as a function of the TcpO2. Statistical analysis revealed no significant linear trend between the macrocirculation status and TcpO2. Biavariate analysis using the Fisher exact test, Mantel-Haenszel tests, and McNemar-Bowker tests also found no significant relationship between macrocirculation and TcpO2. Computed tomographic angiography and Doppler ultrasound are not sufficiently reliable substitutes for TcpO2 measurements in regard to determining the optimal treatment for diabetic patients.

Reproducibility of proximal and distal transcutaneous oxygen pressure measurements during exercise in stage 2 arterial claudication.

Science.gov (United States)

Bouyé, P; Picquet, J; Jaquinandi, V; Enon, B; Leftheriotis, G; Saumet, J-L; Abraham, P

2004-06-01

Although transcutaneous oxygen pressure measurements (tcpO2) are largely used in the investigation of vascular patients, its reproducibility is still debated. Indeed an unpredictable gradient exists between arterial and transcutaneous oxygen pressure. We hypothesised that indices taking into account changes over time and independent of absolute starting values would be more reproducible than other indices. comparative test-retest procedure (1 to 13 days between tests). institutional practice, ambulatory care. 15 subjects with stage 2 claudication. tcpO2 recordings at rest and at exercise during the 2 treadmill tests. calculation of the Delta-from-rest of oxygen pressure index (limb tcpO2 changes minus chest tcpO2 changes), of the resting - or minimal values attained during exercise - of absolute tcpO2 and of the regional perfusion index (regional perfusion index: ration of limb to chest). Both absolute tcpO2 and regional perfusion index at rest showed low reproducibility. During exercise the best reproducibility was attained through Delta-from-rest of oxygen pressure index calculation. Equations from the linear regression analysis (test 2 versus test 1) were 0.88 x -4.2 (r(2)=0.82) at the buttock level and 0.82 x -3.8 (r(2)=0.80) at the calf level. TcpO2 measurement on the calf or buttock during exercise, is a reproducible measurement in patients with vascular claudication, specifically when corrected for exercise-induced systemic pO2 changes trough Delta-from-rest of oxygen pressure calculation.

Java parallel secure stream for grid computing

International Nuclear Information System (INIS)

Chen, J.; Akers, W.; Chen, Y.; Watson, W.

2001-01-01

The emergence of high speed wide area networks makes grid computing a reality. However grid applications that need reliable data transfer still have difficulties to achieve optimal TCP performance due to network tuning of TCP window size to improve the bandwidth and to reduce latency on a high speed wide area network. The authors present a pure Java package called JPARSS (Java Parallel Secure Stream) that divides data into partitions that are sent over several parallel Java streams simultaneously and allows Java or Web applications to achieve optimal TCP performance in a gird environment without the necessity of tuning the TCP window size. Several experimental results are provided to show that using parallel stream is more effective than tuning TCP window size. In addition X.509 certificate based single sign-on mechanism and SSL based connection establishment are integrated into this package. Finally a few applications using this package will be discussed

Synthesis and characterization of tricalcium phosphate ceramics doped with zinc

International Nuclear Information System (INIS)

Kai, K.C.; Marchi, J.; Ussui, V.; Bressiani, A.H.A.

2011-01-01

Due to its biocompatibility, the tricalcium phosphate (TCP) is used as a biomaterial for bone replacement and reconstruction. Zinc (Zn) can replace calcium in the crystal structure of TCP to be added in small quantities, can result in stimulatory effects on bone formation in vitro and in vivo. In this work, pure TCP and Zn-TCP, with general formula (Ca_1_-_xZn_x)_3 (PO_4)_2 and 0 ≤ x ≤ 0.0225, were prepared by wet synthesis, from precursors Ca(OH)_2, H_3PO_4 and ZnO, after calcinated at 800 deg C and characterized by X-ray diffraction, specific surface area, agglomerate size distribution, differential thermal analysis and scanning electron microscopy. The results showed that the addition of small amounts of Zn resulted in TCP with suitable densification and higher specific surface area, may be promising as biomaterial due to the stimulatory effects of zinc associated with suitable mechanical properties of the final material. (author)

Mechanical properties' improvement of a tricalcium phosphate scaffold with poly-l-lactic acid in selective laser sintering

International Nuclear Information System (INIS)

Liu, Defu; Zhuang, Jingyu; Shuai, Cijun; Peng, Shuping

2013-01-01

To improve the mechanical properties of a scaffold fabricated via selective laser sintering (SLS), a small amount (0.5–3 wt%) of poly-l-lactic acid (PLLA) is added to the β-tricalcium phosphate (β-TCP) powder. The fracture toughness of the scaffold prepared with the mixture powder containing 1 wt% PLLA increases by 18.18% and the compressive strength increases by 4.45% compared to the scaffold prepared from the β-TCP powder. The strengthening and toughening is related to the enhancement of β-TCP sintering characteristics via introducing a transient liquid phase in SLS. Moreover, the microcracks caused by the volume expansion due to the β–α phase transformation of TCP are reduced because of the PLLA inhibition function on the phase transformation. However, PLLA additive above 1 wt% would lead to a PLLA residue which will decrease the mechanical properties. The experimental results show that PLLA is an effective sintering aid to improve the mechanical properties of a TCP scaffold. (paper)

Effect of α-naphthylisothiocyanate on blood clearance of 99mTc-phytate in dogs

International Nuclear Information System (INIS)

Shibata, Hiroshi; Kohno, Masahiro; Katoh, Hirotake

1989-01-01

The effect of α-naphthylisothiocyanate (ANIT) on blood clearance of 99m Tc-phytate ( 99m Tc-P) in dogs was examined, and blood clearance test of 99m Tc-P was compared with the cases of serum transaminase test or serum bilirubin test. Serum transaminase and bilirubin levels in dogs increased after ANIT administration, however, the degree of increase in these parameters was much lower than the cases in rats. The disappearance rate of 99m Tc-P from blood in dogs decreased with the increase in dose of ANIT and with the passage of time after the ANIT administration. Changes of the blood clearance of 99m Tc-P after ANIT treatment in dogs may be influenced by the disorder in the hepatocytes rather than in the bile ductule cells. The blood clearance test of 99m Tc-P in dogs showed a sensitive reaction for the acute hepatic dysfunction induced by ANIT equally to the serum transaminase test or the serum bilirubin test. (author)

"Fabrication of arbitrarily shaped carbonate apatite foam based on the interlocking process of dicalcium hydrogen phosphate dihydrate".

Science.gov (United States)

Sugiura, Yuki; Tsuru, Kanji; Ishikawa, Kunio

2017-08-01

Carbonate apatite (CO 3 Ap) foam with an interconnected porous structure is highly attractive as a scaffold for bone replacement. In this study, arbitrarily shaped CO 3 Ap foam was formed from α-tricalcium phosphate (α-TCP) foam granules via a two-step process involving treatment with acidic calcium phosphate solution followed by hydrothermal treatment with NaHCO 3 . The treatment with acidic calcium phosphate solution, which is key to fabricating arbitrarily shaped CO 3 Ap foam, enables dicalcium hydrogen phosphate dihydrate (DCPD) crystals to form on the α-TCP foam granules. The generated DCPD crystals cause the α-TCP granules to interlock with each other, inducing an α-TCP/DCPD foam. The interlocking structure containing DCPD crystals can survive hydrothermal treatment with NaHCO 3 . The arbitrarily shaped CO 3 Ap foam was fabricated from the α-TCP/DCPD foam via hydrothermal treatment at 200 °C for 24 h in the presence of a large amount of NaHCO 3 .

Polyhedral patterns

KAUST Repository

Jiang, Caigui

2015-10-27

We study the design and optimization of polyhedral patterns, which are patterns of planar polygonal faces on freeform surfaces. Working with polyhedral patterns is desirable in architectural geometry and industrial design. However, the classical tiling patterns on the plane must take on various shapes in order to faithfully and feasibly approximate curved surfaces. We define and analyze the deformations these tiles must undertake to account for curvature, and discover the symmetries that remain invariant under such deformations. We propose a novel method to regularize polyhedral patterns while maintaining these symmetries into a plethora of aesthetic and feasible patterns.

Comparative disposition and metabolism of 1,2,3-trichloropropane in rats and mice.

Science.gov (United States)

Mahmood, N A; Overstreet, D; Burka, L T

1991-01-01

1,2,3-Trichloropropane (TCP) has been used as a solvent and degreasing agent and as an intermediate in pesticide manufacture. TCP is currently the subject of a National Toxicology Program chronic toxicity study. The present study is part of a larger effort to characterize the toxicity of TCP. Following acute oral exposure of male and female F344 rats (30 mg/kg) and male B6C3F1 mice (30 and 60 mg/kg), TCP was rapidly absorbed, metabolized, and excreted. The major route of excretion of TCP was in the urine. By 60 hr postdosing, rats had excreted 50% and mice 65% of the administered dose by this route. Exhalation as 14CO2 and excretion in the feces each accounted for 20% of the total dose in 60 hr rats and 20 and 15%, respectively, in mice. No apparent sex-related differences were observed in the ability of the rats to excrete TCP-derived radioactivity. At 60 hr, TCP-derived radioactivity was most concentrated in the liver, kidney, and forestomach in both rats and male mice. Male mice eliminated TCP-derived radioactivity more rapidly than rats and lower concentrations of radioactivity were found in tissues 60 hr after dosing in mice. Two urinary metabolites were isolated and identified by NMR, mass spectroscopy, and comparison with synthetic standards, as N-acetyl- and S-(3-chloro-2-hydroxypropyl)cysteine. Analyses of the early urine (0-6 hr) showed this mercapturic acid to be the major metabolite in rat urine and was only a minor component in mouse urine. 2-(S-Glutathionyl)malonic acid was identified by NMR and mass spectrometry and by chemical synthesis as the major biliary metabolite in rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Under conditions of large geometric miss, tumor control probability can be higher for static gantry intensity-modulated radiation therapy compared to volume-modulated arc therapy for prostate cancer

International Nuclear Information System (INIS)

Balderson, Michael; Brown, Derek; Johnson, Patricia; Kirkby, Charles

2016-01-01

The purpose of this work was to compare static gantry intensity-modulated radiation therapy (IMRT) with volume-modulated arc therapy (VMAT) in terms of tumor control probability (TCP) under scenarios involving large geometric misses, i.e., those beyond what are accounted for when margin expansion is determined. Using a planning approach typical for these treatments, a linear-quadratic–based model for TCP was used to compare mean TCP values for a population of patients who experiences a geometric miss (i.e., systematic and random shifts of the clinical target volume within the planning target dose distribution). A Monte Carlo approach was used to account for the different biological sensitivities of a population of patients. Interestingly, for errors consisting of coplanar systematic target volume offsets and three-dimensional random offsets, static gantry IMRT appears to offer an advantage over VMAT in that larger shift errors are tolerated for the same mean TCP. For example, under the conditions simulated, erroneous systematic shifts of 15 mm directly between or directly into static gantry IMRT fields result in mean TCP values between 96% and 98%, whereas the same errors on VMAT plans result in mean TCP values between 45% and 74%. Random geometric shifts of the target volume were characterized using normal distributions in each Cartesian dimension. When the standard deviations were doubled from those values assumed in the derivation of the treatment margins, our model showed a 7% drop in mean TCP for the static gantry IMRT plans but a 20% drop in TCP for the VMAT plans. Although adding a margin for error to a clinical target volume is perhaps the best approach to account for expected geometric misses, this work suggests that static gantry IMRT may offer a treatment that is more tolerant to geometric miss errors than VMAT.

Time-dependent efficiency measurements of polymer solar cells with dye additives: unexpected initial increase of efficiency

Science.gov (United States)

Bandaccari, Kyle J.; Chesmore, Grace E.; Bugaj, Mitchel; Valverde, Parisa Tajalli-Tehrani; Barber, Richard P.; McNelis, Brian J.

2018-04-01

We report the effects of the addition of two azo-dye additives on the time-dependent efficiency of polymer solar cells. Although the maximum efficiencies of devices containing different amounts of dye do not vary greatly over the selected concentration range, the time dependence results reveal a surprising initial increase in efficiency in some samples. We observe this effect to be correlated with a leakage current, although a specific mechanism is not yet identified. We also present the measured lifetimes of these solar cells, and find that variations in dye concentrations produce a small effect at most. Characterization of the bulk heterojunction layer (active layer) morphology using atomic-force microscope (AFM) imaging reveals reordering patterns which suggest that the primary effects of the dyes arise via structural, not absorptive, characteristics.

At the edge of the earth's magnetosphere: a survey by the AMPTE UKS spacecraft

International Nuclear Information System (INIS)

Bryant, D.A.; Riggs, S.

1988-10-01

A survey is made, using measurements from the AMPTE-UKS spacecraft, of the interaction between plasmas of solar and terrestrial origin at the outer edge of the Earth's magnetosphere. The first results are presented of a new type of analysis which aims to clarify the nature of the boundary layer that develops between the two plasmas by re-ordering, on the basis of a consistent relationship between electron density and temperature and the normally erratic progress made by a spacecraft across the constantly moving region. Distinctive patterns found consistently for the electron and ion transitions suggest that diffusion, viscosity and loss to the atmosphere govern the boundary layer. Electron acceleration within the boundary layer is identified; and its cause, and relevance to dayside auroral precipitation are discussed. (author)

Performance Evaluation of IEEE 802.11ah Networks With High-Throughput Bidirectional Traffic.

Science.gov (United States)

Šljivo, Amina; Kerkhove, Dwight; Tian, Le; Famaey, Jeroen; Munteanu, Adrian; Moerman, Ingrid; Hoebeke, Jeroen; De Poorter, Eli

2018-01-23

So far, existing sub-GHz wireless communication technologies focused on low-bandwidth, long-range communication with large numbers of constrained devices. Although these characteristics are fine for many Internet of Things (IoT) applications, more demanding application requirements could not be met and legacy Internet technologies such as Transmission Control Protocol/Internet Protocol (TCP/IP) could not be used. This has changed with the advent of the new IEEE 802.11ah Wi-Fi standard, which is much more suitable for reliable bidirectional communication and high-throughput applications over a wide area (up to 1 km). The standard offers great possibilities for network performance optimization through a number of physical- and link-layer configurable features. However, given that the optimal configuration parameters depend on traffic patterns, the standard does not dictate how to determine them. Such a large number of configuration options can lead to sub-optimal or even incorrect configurations. Therefore, we investigated how two key mechanisms, Restricted Access Window (RAW) grouping and Traffic Indication Map (TIM) segmentation, influence scalability, throughput, latency and energy efficiency in the presence of bidirectional TCP/IP traffic. We considered both high-throughput video streaming traffic and large-scale reliable sensing traffic and investigated TCP behavior in both scenarios when the link layer introduces long delays. This article presents the relations between attainable throughput per station and attainable number of stations, as well as the influence of RAW, TIM and TCP parameters on both. We found that up to 20 continuously streaming IP-cameras can be reliably connected via IEEE 802.11ah with a maximum average data rate of 160 kbps, whereas 10 IP-cameras can achieve average data rates of up to 255 kbps over 200 m. Up to 6960 stations transmitting every 60 s can be connected over 1 km with no lost packets. The presented results enable the fine tuning

The New World Information Order.

Science.gov (United States)

Masmoudi, Mustapha

1979-01-01

Argues for a reordering of the present conception of world information transmission dominated by the developed nations and characterized by imbalances in the political, legal, and technico-financial spheres. (JMF)

Phosphate solubilizing ability of two Arctic Aspergillus niger strains

Directory of Open Access Journals (Sweden)

Shiv Mohan Singh,

2011-06-01

Full Text Available Many filamentous fungi were isolated from the soils of Ny-Ålesund, Spitsbergen, Svalbard, and were screened in vitro for their phosphate solubilizing ability. Two strains of Aspergillus niger showed good tricalcium phosphate (TCP solubilizing ability in Pikovskaya's medium. The TCP solubilization index was calculated at varying levels of pH and temperatures. The ability of Aspergillus niger strain-1 to solubilize and release inorganic-P was 285 µg ml–1, while Aspergillus niger strain-2 solubilized 262 µg ml–1 from 0.5% TCP after seven days. This is the first report of TCP solubilization by Arctic strains that may serve as very good phosphate solubilizers in the form of biofertilizer.

Continuous cellularization of calcium phosphate hybrid scaffolds induced by plasma polymer activation

Energy Technology Data Exchange (ETDEWEB)

Bergemann, Claudia [University Medical Center Rostock, Cell Biology, Schillingallee 69, D-18057 Rostock (Germany); Cornelsen, Matthias [University of Rostock, Fluid Technology and Microfluidics, Justus-von-Liebig Weg 6, D-18059 Rostock (Germany); Quade, Antje [Leibniz-Institute for Plasma Science and Technology (INP), Felix-Hausdorff-Str. 2, D-17489 Greifswald (Germany); Laube, Thorsten; Schnabelrauch, Matthias [INNOVENT e.V., Biomaterials Department, Pruessingstrasse 27B, D-07745 Jena (Germany); Rebl, Henrike [University Medical Center Rostock, Cell Biology, Schillingallee 69, D-18057 Rostock (Germany); Weißmann, Volker [Institute for Polymer Technologies (IPT) e.V., Alter Holzhafen 19, D-23966 Wismar (Germany); Seitz, Hermann [University of Rostock, Fluid Technology and Microfluidics, Justus-von-Liebig Weg 6, D-18059 Rostock (Germany); Nebe, Barbara, E-mail: barbara.nebe@med.uni-rostock.de [University Medical Center Rostock, Cell Biology, Schillingallee 69, D-18057 Rostock (Germany)

2016-02-01

The generation of hybrid materials based on β-tricalcium phosphate (TCP) and various biodegradable polymers like poly(L-lactide-co-D,L-lactide) (PLA) represents a common approach to overcoming the disadvantages of pure TCP devices. These disadvantages lie in TCP's mechanical properties, such as brittleness. The positive characteristic of PLA — improvement of compressive strength of calcium phosphate scaffolds – is diametrically opposed to its cell attractiveness. Therefore, the objective of this work was to optimize osteoblast migration and cellularization inside a three-dimensionally (3D) printed, PLA polymer stabilized TCP hybrid scaffold by a plasma polymer process depositing amino groups via allylamine. MG-63 osteoblastic cells inside the 10 mm hybrid scaffold were dynamically cultivated for 14 days in a 3D model system integrated in a perfusion reactor. The whole TCP/PLA hybrid scaffold was continuously colonized due to plasma polymerized allylamine activation inducing the migration potential of osteoblasts. - Highlights: • Mechanical stabilization of β-tricalcium phosphate scaffolds by PLA infiltration • Hybrid scaffolds with higher cell attraction due to plasma polymerized allylamine • 3D perfusion in vitro model for observation of cell migration inside scaffolds • Enhanced cell migration within plasma polymer coated TCP hybrid scaffolds.

Continuous cellularization of calcium phosphate hybrid scaffolds induced by plasma polymer activation

International Nuclear Information System (INIS)

Bergemann, Claudia; Cornelsen, Matthias; Quade, Antje; Laube, Thorsten; Schnabelrauch, Matthias; Rebl, Henrike; Weißmann, Volker; Seitz, Hermann; Nebe, Barbara

2016-01-01

The generation of hybrid materials based on β-tricalcium phosphate (TCP) and various biodegradable polymers like poly(L-lactide-co-D,L-lactide) (PLA) represents a common approach to overcoming the disadvantages of pure TCP devices. These disadvantages lie in TCP's mechanical properties, such as brittleness. The positive characteristic of PLA — improvement of compressive strength of calcium phosphate scaffolds – is diametrically opposed to its cell attractiveness. Therefore, the objective of this work was to optimize osteoblast migration and cellularization inside a three-dimensionally (3D) printed, PLA polymer stabilized TCP hybrid scaffold by a plasma polymer process depositing amino groups via allylamine. MG-63 osteoblastic cells inside the 10 mm hybrid scaffold were dynamically cultivated for 14 days in a 3D model system integrated in a perfusion reactor. The whole TCP/PLA hybrid scaffold was continuously colonized due to plasma polymerized allylamine activation inducing the migration potential of osteoblasts. - Highlights: • Mechanical stabilization of β-tricalcium phosphate scaffolds by PLA infiltration • Hybrid scaffolds with higher cell attraction due to plasma polymerized allylamine • 3D perfusion in vitro model for observation of cell migration inside scaffolds • Enhanced cell migration within plasma polymer coated TCP hybrid scaffolds

A novel immunochromatographic electrochemical biosensor for highly sensitive and selective detection of trichloropyridinol, a biomarker of exposure to chlorpyrifos.

Science.gov (United States)

Wang, Limin; Lu, Donglai; Wang, Jun; Du, Dan; Zou, Zhexiang; Wang, Hua; Smith, Jordan N; Timchalk, Charles; Liu, Fengquan; Lin, Yuehe

2011-02-15

We present a novel portable immunochromatographic electrochemical biosensor (IEB) for simple, rapid, and sensitive biomonitoring of trichloropyridinol (TCP), a metabolite biomarker of exposure to organophosphorus insecticides. Our new approach takes the advantage of immunochromatographic test strip for a rapid competitive immunoreaction and a disposable screen-printed carbon electrode for a rapid and sensitive electrochemical analysis of captured HRP labeling. Several key experimental parameters (e.g. immunoreaction time, the amount of HRP labeled TCP, concentration of the substrate for electrochemical measurements, and the blocking agents for the nitrocellulose membrane) were optimized to achieve a high sensitivity, selectivity and stability. Under optimal conditions, the IEB has demonstrated a wide linear range (0.1-100 ng/ml) with a detection limit as low as 0.1 ng/ml TCP. Furthermore, the IEB has been successfully applied for biomonitoring of TCP in the rat plasma samples with in vivo exposure to organophosphorus insecticides like Chlorpyrifos-oxon (CPF-oxon). The IEB thus opens up new pathways for designing a simple, rapid, clinically accurate, and quantitative tool for TCP detection, as well as holds a great promise for in-field screening of metabolite biomarkers, e.g., TCP, for humans exposed to organophosphorus insecticides. Copyright © 2010 Elsevier B.V. All rights reserved.

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

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Mira Moussa

2015-04-01

Full Text Available 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.

Chlorpyrifos exerts opposing effects on axonal and dendritic growth in primary neuronal cultures

International Nuclear Information System (INIS)

Howard, Angela S.; Bucelli, Robert; Jett, David A.; Bruun, Donald; Yang, Dongren; Lein, Pamela J.

2005-01-01

Evidence that children are widely exposed to organophosphorus pesticides (OPs) and that OPs cause developmental neurotoxicity in animal models raises significant concerns about the risks these compounds pose to the developing human nervous system. Critical to assessing this risk is identifying specific neurodevelopmental events targeted by OPs. Observations that OPs alter brain morphometry in developing rodents and inhibit neurite outgrowth in neural cell lines suggest that OPs perturb neuronal morphogenesis. However, an important question yet to be answered is whether the dysmorphogenic effect of OPs reflects perturbation of axonal or dendritic growth. We addressed this question by quantifying axonal and dendritic growth in primary cultures of embryonic rat sympathetic neurons derived from superior cervical ganglia (SCG) following in vitro exposure to chlorpyrifos (CPF) or its metabolites CPF-oxon (CPFO) and trichloropyridinol (TCP). Axon outgrowth was significantly inhibited by CPF or CPFO, but not TCP, at concentrations ≥0.001 μM or 0.001 nM, respectively. In contrast, all three compounds enhanced BMP-induced dendritic growth. Acetylcholinesterase was inhibited only by the highest concentrations of CPF (≥1 μM) and CPFO (≥1 nM); TCP had no effect on this parameter. In summary, these compounds perturb neuronal morphogenesis via opposing effects on axonal and dendritic growth, and both effects are independent of acetylcholinesterase inhibition. These findings have important implications for current risk assessment practices of using acetylcholinesterase inhibition as a biomarker of OP neurotoxicity and suggest that OPs may disrupt normal patterns of neuronal connectivity in the developing nervous system

Deep Packet/Flow Analysis using GPUs

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Gong, Qian [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Wu, Wenji [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); DeMar, Phil [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

2017-11-12

Deep packet inspection (DPI) faces severe performance challenges in high-speed networks (40/100 GE) as it requires a large amount of raw computing power and high I/O throughputs. Recently, researchers have tentatively used GPUs to address the above issues and boost the performance of DPI. Typically, DPI applications involve highly complex operations in both per-packet and per-flow data level, often in real-time. The parallel architecture of GPUs fits exceptionally well for per-packet network traffic processing. However, for stateful network protocols such as TCP, their data stream need to be reconstructed in a per-flow level to deliver a consistent content analysis. Since the flow-centric operations are naturally antiparallel and often require large memory space for buffering out-of-sequence packets, they can be problematic for GPUs, whose memory is normally limited to several gigabytes. In this work, we present a highly efficient GPU-based deep packet/flow analysis framework. The proposed design includes a purely GPU-implemented flow tracking and TCP stream reassembly. Instead of buffering and waiting for TCP packets to become in sequence, our framework process the packets in batch and uses a deterministic finite automaton (DFA) with prefix-/suffix- tree method to detect patterns across out-of-sequence packets that happen to be located in different batches. In conclusion, evaluation shows that our code can reassemble and forward tens of millions of packets per second and conduct a stateful signature-based deep packet inspection at 55 Gbit/s using an NVIDIA K40 GPU.

Doped tricalcium phosphate bone tissue engineering scaffolds using sucrose as template and microwave sintering: enhancement of mechanical and biological properties.

Science.gov (United States)

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.

Effect of Casein Phosphopeptide-Amorphous Calcium Phosphate and Three Calcium Phosphate on Enamel Microhardness.

Science.gov (United States)

Haghgou, En Hr; Haghgoo, Roza; Roholahi, Mohamad R; Ghorbani, Zahra

2017-07-01

This study aims to investigate the effect of casein phos-phopeptide-amorphous calcium phosphate and three calcium phosphate (CPP-ACP and TCP) on increasing the microhardness of human enamel after induction of erosion. A total of 26 healthy human-impacted third molar teeth were chosen, and their hardness measured using a microhardness testing machine. The samples were immersed in Coca Cola (pH = 4.7) for 8 minutes. Then, micro-hardness was measured again, and these samples were randomly divided into four groups (two control groups and two experimental groups). (1) Negative control group: Artificial saliva was used for 10 minutes, (2) positive control group: Fluoride gel was used for 10 minutes, (3) β-TCP group: TCP was used for 10 minutes, (4) CCP-ACP group: CCP-ACP was used for 10 minutes. The final microhardness of those samples was measured, and the changes in microhardness of teeth within group and between groups were analyzed using the paired and analysis of variance tests respectively. Results were considered statistically significant at a level of p < 0.05. No significant difference was observed in microhard-ness between CPP-ACP group and TCP group (p = 0.368) during the time microhardness significantly dropped after soaking in soda. Casein phosphopeptide-amorphous calcium phosphate and TCP increased the microhardness of teeth. The increase in hardness in the TCP group was higher than in the CPP-ACP group, but this difference was not significant (p = 0.36). Casein phosphopeptide-amorphous calcium phosphate and TCP can affect the remineralization of erosive lesions.

Polyhedral patterns

KAUST Repository

Jiang, Caigui; Tang, Chengcheng; Vaxman, Amir; Wonka, Peter; Pottmann, Helmut

2015-01-01

We study the design and optimization of polyhedral patterns, which are patterns of planar polygonal faces on freeform surfaces. Working with polyhedral patterns is desirable in architectural geometry and industrial design. However, the classical

Diagnosis of the hypothenar hammer syndrome by high-resolution contrast-enhanced MR angiography

Energy Technology Data Exchange (ETDEWEB)

Winterer, J.T.; Ghanem, N.; Schaefer, O.; Lehnhardt, S.; Thuerl, C.; Laubenberger, J. [Department of Diagnostic Radiology, University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg (Germany); Roth, M. [Center of Geriatric Medicine and Gerontology Freiburg, University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg (Germany); Horch, R.E. [Department of Plastic and Hand Surgery, University of Freiburg, Hugstetter Strasse 55, 79106 Freiburg (Germany)

2002-10-01

Our objective was to describe the imaging features of hypothenar hammer syndrome using minimally invasive contrast-enhanced MR angiography in comparison with oscillography study. In five patients with hypothenar hammer syndrome Gd-BOPTA-enhanced elliptically reordered 3D pulse sequence MR was compared with oscillography findings and clinical symptoms focusing on angiographic appearance of vessel injury, distribution pattern of hand vasculature and joining branches between the radial and ulnar artery supply. All patients showed segmental occlusion at the site of trauma impact with varying involvement of the superficial palmar arch, common volar digital arteries. Embolic disease was present in 50% of patients and could be clearly identified with MRA. Good correspondence was found between angiographic appearance including the presence of collaterals, clinical symptoms and oscillography. Bilateral comparison was helpful in distinguishing between vessel variants and pathology. Bilateral Gd-BOPTA-enhanced MR angiography is a minimally invasive method to depict clearly the localization and extent of vessel injury in hypothenar hammer syndrome providing valuable information about distribution pattern of hand vasculature and presence of collaterals; however, no flow data can be obtained. (orig.)

Diagnosis of the hypothenar hammer syndrome by high-resolution contrast-enhanced MR angiography

International Nuclear Information System (INIS)

Winterer, J.T.; Ghanem, N.; Schaefer, O.; Lehnhardt, S.; Thuerl, C.; Laubenberger, J.; Roth, M.; Horch, R.E.

2002-01-01

Our objective was to describe the imaging features of hypothenar hammer syndrome using minimally invasive contrast-enhanced MR angiography in comparison with oscillography study. In five patients with hypothenar hammer syndrome Gd-BOPTA-enhanced elliptically reordered 3D pulse sequence MR was compared with oscillography findings and clinical symptoms focusing on angiographic appearance of vessel injury, distribution pattern of hand vasculature and joining branches between the radial and ulnar artery supply. All patients showed segmental occlusion at the site of trauma impact with varying involvement of the superficial palmar arch, common volar digital arteries. Embolic disease was present in 50% of patients and could be clearly identified with MRA. Good correspondence was found between angiographic appearance including the presence of collaterals, clinical symptoms and oscillography. Bilateral comparison was helpful in distinguishing between vessel variants and pathology. Bilateral Gd-BOPTA-enhanced MR angiography is a minimally invasive method to depict clearly the localization and extent of vessel injury in hypothenar hammer syndrome providing valuable information about distribution pattern of hand vasculature and presence of collaterals; however, no flow data can be obtained. (orig.)

Dynamics of asymmetric non-polymeric binary glass formers—A nuclear magnetic resonance and dielectric spectroscopy study

Energy Technology Data Exchange (ETDEWEB)

Pötzschner, B.; Mohamed, F.; Lichtinger, A.; Bock, D.; Rössler, E. A., E-mail: ernst.roessler@uni-bayreuth.de [Experimentalphysik II, Universität Bayreuth, 95440 Bayreuth (Germany)

2015-10-21

We study a dynamically asymmetric binary glass former with the low-T{sub g} component m-tri-cresyl phosphate (m-TCP: T{sub g} = 206 K) and a spirobichroman derivative as a non-polymeric high-T{sub g} component (T{sub g} = 382 K) by means of {sup 1}H nuclear magnetic resonance (NMR), {sup 31}P NMR, and dielectric spectroscopy which allow component-selectively probing the dynamics. The entire concentration range is covered, and two main relaxation processes with two T{sub g} are identified, T{sub g1} and T{sub g2}. The slower one is attributed to the high-T{sub g} component (α{sub 1}-process), and the faster one is related to the m-TCP molecules (α{sub 2}-process). Yet, there are indications that a small fraction of m-TCP is associated also with the α{sub 1}-process. While the α{sub 1}-relaxation only weakly broadens upon adding m-TCP, the α{sub 2}-relaxation becomes extremely stretched leading to quasi-logarithmic correlation functions at low m-TCP concentrations—as probed by {sup 31}P NMR stimulated echo experiments. Frequency-temperature superposition does not apply for the α{sub 2}-process and it reflects an isotropic, liquid-like motion which is observed even below T{sub g1}, i.e., in the matrix of the arrested high-T{sub g} molecules. As proven by 2D {sup 31}P NMR, the corresponding dynamic heterogeneities are of transient nature, i.e., exchange occurs within the distribution G(lnτ{sub α2}). At T{sub g1} a crossover is found for the temperature dependence of (mean) τ{sub α2}(T) from non-Arrhenius above to Arrhenius below T{sub g1} which is attributed to intrinsic confinement effects. This “fragile-to-strong” transition also leads to a re-decrease of T{sub g2}(c{sub m−TCP}) at low concentration c{sub m−TCP}, i.e., a maximum is observed in T{sub g2}(c{sub m−TCP}) while T{sub g1}(c{sub m−TCP}) displays the well-known plasticizer effect. Although only non-polymeric components are involved, we re-discover essentially all features previously

Obtención de fibras policristalinas de b-Ca3(PO42 para su empleo como material de relleno en procesos de reparación ósea

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Guitián-Rivera, F.

2007-04-01

Full Text Available b-TCP is a calcium phosphate ceramic widely employed by orthopaedic restorative surgery as a filler material in bone healing processes, due to its great osteoconductive capacity and great resorption rates. This material is available in several forms such as powders, dense and porous blocks, etc, depending on the pathology and the osseous defect to be treated. As an alternative to the b-TCP forms already available in the market, this work describes how to produce polycrystalline fibres by extruding plastic mixtures prepared with b-TCP powders, methyl cellulose (MC and water. The rheology of the mixtures was studied versus time and frequency. The obtained fibres have different sizes and characteristics upon to the composition and rheology of the mixtures. The obtained diameters are between 150 μm and 350 μm. Finally, it has been prepared biphasic composites b-TCP/Hidroxylapatite (HA with controlled microstructure, by employing the obtained fibres.El b-Ca3(PO42 (b-TCP es un fosfato cálcico ampliamente empleado como material de relleno por la cirugía ortopédico restauradora en procesos de curación ósea, debido a su capacidad osteoconductora y alta tasa de biorreabsorción. Se emplea con distintas formas, tales como granulados, piezas compactas, piezas porosas, etc, dependiendo de la patología y el tipo de defecto óseo a tratar. Como alternativa a las formas ya existentes en el mercado, en el presente trabajo se obtuvieron fibras policristalinas de b-TCP por extrusión de masas plásticas preparadas a partir de polvo de b-TCP y metilcelulosa (MC en agua. Se estudió la reología de las pastas y su comportamiento frente al esfuerzo y a la temperatura. Las fibras presentan distintos grosores, y características, que se obtienen variando el diámetro de las boquillas, la composición y la reología de las pastas. Los diámetros obtenidos van desde 350 μm a 150 μm. Finalmente se obtuvieron composites bifásicos b-TCP-Hidroxiapatito con

A fast inner product processor based on equal alignments

Energy Technology Data Exchange (ETDEWEB)

Smith, S.P.; Torng, H.C.

1985-11-01

Inner product computation is an important operation, invoked repeatedly in matrix multiplications. A high-speed inner product processor can be very useful (among many possible applications) in real-time signal processing. This paper presents the design of a fast inner product processor, with appreciably reduced latency and cost. The inner product processor is implemented with a tree of carry-propagate or carry-save adders; this structure is obtained with the incorporation of three innovations in the conventional multiply/add tree: The leaf-multipliers are expanded into adder subtrees, thus achieving an O(log Nb) latency, where N denotes the number of elements in a vector and b the number of bits in each element. The partial products, to be summed in producing an inner product, are reordered according to their ''minimum alignments.'' This reordering brings approximately a 20% savings in hardware-including adders and data paths. The reduction in adder widths also yields savings in carry propagation time for carry-propagate adders. For trees implemented with carry-save adders, the partial product reordering also serves to truncate the carry propagation chain in the final propagation stage by 2 log b - 1 positions, thus significantly reducing the latency further. A form of the Baugh and Wooley algorithm is adopted to implement two's complement notation with changes only in peripheral hardware.

Trichoderma spp. decrease Fusarium root rot in common bean

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Hudson Teixeira

2012-12-01

Full Text Available The effectiveness of six Trichoderma-based commercial products (TCP in controlling Fusarium root rot (FRR in common bean was assessed under field conditions. Three TCP, used for seed treatment or applied in the furrow, increased seedling emergence as much as the fungicide fludioxonil. FRR incidence was not affected, but all TCP and fludioxonil reduced the disease severity, compared to control. Application of Trichoderma-based products was as effective as that of fludioxonil in FRR management.

78 FR 30798 - Notice of Intent To Request Public Comments

Science.gov (United States)

2013-05-23

... is appended. The Commission, in its discretion, may modify or reorder the schedule in the future to... Concerning Franchising. 681 Identity Theft [Red Flag] 2018. Rules. 24 Guides for Select Leather and 2019...

Crystallization and crystallographic analysis of the Rhodococcus rhodochrous NCIMB 13064 DhaA mutant DhaA31 and its complex with 1,2,3-trichloropropane.

Science.gov (United States)

Lahoda, Maryna; Chaloupkova, Radka; Stsiapanava, Alena; Damborsky, Jiri; Kuta Smatanova, Ivana

2011-03-01

Haloalkane dehalogenases hydrolyze carbon-halogen bonds in a wide range of halogenated aliphatic compounds. The potential use of haloalkane dehalogenases in bioremediation applications has stimulated intensive investigation of these enzymes and their engineering. The mutant DhaA31 was constructed to degrade the anthropogenic compound 1,2,3-trichloropropane (TCP) using a new strategy. This strategy enhances activity towards TCP by decreasing the accessibility of the active site to water molecules, thereby promoting formation of the activated complex. The structure of DhaA31 will help in understanding the structure-function relationships involved in the improved dehalogenation of TCP. The mutant protein DhaA31 was crystallized by the sitting-drop vapour-diffusion technique and crystals of DhaA31 in complex with TCP were obtained using soaking experiments. Both crystals belonged to the triclinic space group P1. Diffraction data were collected to high resolution: to 1.31 Å for DhaA31 and to 1.26 Å for DhaA31 complexed with TCP.

Comparison between evaluating methods about the protocols of different dose distributions in radiotherapy

International Nuclear Information System (INIS)

Ju Yongjian; Chen Meihua; Sun Fuyin; Zhang Liang'an; Lei Chengzhi

2004-01-01

Objective: To study the relationship between tumor control probability (TCP) or equivalent uniform dose (EUD) and the heterogeneity degree of the dose changes with variable biological parameter values of the tumor. Methods: According to the definitions of TCP and EUD, calculating equations were derived. The dose distributions in the tumor were assumed to be Gaussian ones. The volume of the tumor was divided into several voxels, and the absorbed doses of these voxels were simulated by Monte Carlo methods. Then with the different values of radiosensitivity (α) and potential doubling time of the clonogens (T p ), the relationships between TCP or EUD and the standard deviation of dose (S d ) were evaluated. Results: The TCP-S d curves were influenced by the variable α and T p values, but the EUD-S d curves showed little variation. Conclusion: When the radiotherapy protocols with different dose distributions are compared, if the biological parameter values of the tumor have been known exactly, it's better to use the TCP, otherwise the EUD will be preferred