Synchronous Delivery Research Articles

PH-responsive complexes using prefunctionalized polymers for synchronous delivery of doxorubicin and siRNA to cancer cells

A nanocarrier delivery system that can simultaneously deliver a chemotherapeutic drug and siRNA to the tumor is emerging as a promising treatment strategy for cancer treatment. In this study, a multifunctional PHD/PPF/siRNA complexes was developed by one-step assembly of prefunctionalized polymers: PEI–HZ–DOX (PHD) and PEI-PEG-Folate (PPF) with siRNA. The PHD, a conjugate of PEI (polyethylenimine) with doxorubicin (DOX) via a pH-responsive hydrazone linkage, enables pH-controlled drug release. The PPF, a tumor-targeting folate ligand conjugated to PEI using polyethyleneglycol (PEG) as a linker, enables immune evasion and cell-specific targeting. The prefunctionalized PHD and PPF as well as the self-assembly complexes reveals advantage on safety in further application for siRNA delivery. By exploiting distinct triple ratios of PHD, PPF and siRNA during nanocomplexes formulation, the folate surface density, DOX loading amount and siRNA complexation can be precisely and reproducibly changed. The studies showed that the complexes was capable of delivering siRNA and DOX to cancerous cells and release synchronously in cell by acid-triggered manner, i.e. hydrazone bond cleavage and endosome/lysosome escape using flow cytometry and confocal laser scanning microscopy analysis. The results highlight the potential for therapeutic gene silencing in vitro and in vivo using RT-PCR and non-invasive in vivo imaging systems. The PHD/PPF/siRNA complexes can increase DOX and siRNA accumulation in cancerous cells and decrease the nonspecific distribution in normal tissues by the combination of EPR effect of nanocarriers, pH-triggered drug release, folate-mediated targeted delivery, and synergistic action of DOX and siRNA.

Abstract 248: Continuous Chest Compressions with Interposed Ventilations Are Associated with Improved Outcomes from Suspected Asphyxial Arrest

Background: A continuous chest compression (CCC) approach to CPR avoids pauses that decrease coronary perfusion pressure. However, the ability to provide adequate ventilation during CCC remains unclear. Cardiopulmonary arrest (CPA) victims with suspected asphyxia would be expected to be the most impacted by inadequate ventilation during CPR. Objective: To explore the impact of CCC on outcome from inpatients with suspected asphyxial CPA. Methods: This study was conducted in two urban university hospitals from 2005-09. The Advanced Resuscitation Training (ART) program was implemented in 2007. The ART program advocates CCC with interposed ventilations performed at a 10:1 ratio. Ventilations are initiated with the onset of compression recoil for both unprotected and protected airways. Data for all CPAs are entered into a resuscitation database. CPA events are categorized based on suspected etiology. Survival-to-discharge rates before and after implementation of the ART protocol were evaluated using chi-square analysis including test for trend. Ventilation rates were measured over the final 18 months of the study. Results: A total of 140 inpatients had suspected asphyxial CPA during the study period. Survival-to-discharge increased from 21.8% to 47.2% following implementation of the ART CCC protocol (p<0.001). Average ventilation rates associated with CCC were 9.7 breaths/min. Conclusions: An inpatient CCC protocol with ventilations interposed at a 10:1 ratio was associated with marked improvements in outcome among patients with suspected asphyxial CPA. These data suggest that adequate ventilation can be achieved with synchronous delivery of breaths with the recoil phase of compressions. Controlled ventilation rates were also achieved.

Factors related to rural school administrators’ satisfaction with distance education

The purpose of this study was to examine rural school district administrators’ satisfaction with distance education in the United States and to identify factors that may contribute to their satisfaction. Telephone interviews were conducted with administrators in randomly selected rural districts across the country. Analyses revealed that students’ preparation in their study and computer skills as well as the use of synchronous delivery formats were related to administrators’ satisfaction with distance education. Results imply that students’ study and computer skills should be addressed as needed and, when feasible, synchronous delivery formats used in order to possibly bolster districts’ satisfaction with and effective use of distance education.

Delivering hydrophilic and hydrophobic chemotherapeutics simultaneously by magnetic mesoporous silica nanoparticles to inhibit cancer cells

Using nanoparticles to deliver chemotherapeutics offers new opportunities for cancer therapy, but challenges still remain when they are used for the delivery of multiple drugs, especially for the synchronous delivery of hydrophilic and hydrophobic drugs in combination therapies. In this paper, we developed an approach to deliver hydrophilic–hydrophobic anticancer drug pairs by employing magnetic mesoporous silica nanoparticles (MMSNs). We prepared 50 nm-sized MMSNs with uniform pore size and evaluated their capability for the loading of two combinations of chemotherapeutics, namely doxorubicin–paclitaxel and doxorubicin–rapamycin, by means of sequential adsorption from the aqueous solution of doxorubicin and nonaqueous solutions of paclitaxel or rapamycin. Experimental results showed that the present strategy successfully realized the co-loading of hydrophilic and hydrophobic drugs with high-loading content and widely tunable ratio range. We elaborate on the theory behind the molecular interaction between the silica hydroxyl groups and drug molecules, which underlie the controllable loading, and the subsequent release of the drug pairs. Then we demonstrate that the multidrug-loaded MMSNs could be easily internalized by A549 human pulmonary adenocarcinoma cells, and produce enhanced tumor cell apoptosis and growth inhibition as compared to single-drug loaded MMSNs. Our study thus realized simultaneous and dose-tunable delivery of hydrophilic and hydrophobic drugs, which were endowed with improved anticancer efficacy. This strategy could be readily extended to other chemotherapeutic combinations and might have clinically translatable significance.

SIG 8 Perspectives Vol. 12, No. 1, December 2011

SIG 8 Perspectives Vol. 12, No. 1, December 2011

Telepractice Supported Delivery of LSVT®LOUD

This article outlines the essential features and underlying principles of Lee Silverman Voice Treatment (LSVT®LOUD) and explores the delivery of this treatment via telepractice. A detailed summary of the core features of LSVT®LOUD and the principles underpinning this treatment are presented. Current evidence to support the feasibility and validity of synchronous and asynchronous delivery of LSVT®LOUD to people with Parkinson disease (PD) is reviewed. Technology specifications, cost-benefit analyses, and patient satisfaction are discussed. The challenges involved in delivery of LSVT®LOUD via telepractice, such as inconsistent audio and video quality during videoconferencing, accurate measurement of vocal parameters, technical skill level of the clinician, and patient candidacy, are highlighted. LSVT®LOUD can be effectively and reliably delivered via telepractice. Improvements in telecommunications are required to overcome some of the technology challenges encountered in this mode of delivery. Positive benefits of online treatment in relation to savings in time and money and reduced carer burden are emerging. Patient satisfaction with telepractice in the management of the speech disorder associated with PD is high. The uptake of LSVT®LOUD into telepractice is likely to steadily increase with advances in mobile technologies and web-based applications designed to deliver this treatment.

Synchronous multicast and broadcast service in multi-rate IEEE 802.16j WiMAX relay network

IEEE 802.16j Mobile Multihop Relay Standard defines multi-hop relay operation in a WiMAX system. It uses a novel synchronous multicast and broadcast transmission mechanism to achieve macro diversity. With the newly introduced synchronous delivery constraint, the multicast data delivery algorithm should be designed differently to enhance system performance. This paper provides Multi-Rate Selection Algorithm (MRSA) for multicast and broadcast (MBS) data delivery. It could reduce the data distribution delay from the BS to all the RSs. Besides, we also propose the path selection algorithm to further improve the effectiveness of MRSA. Our simulation results show that using MRSA with our shortest-path path selection algorithm, the delay for data delivery in 802.16j MBS system could be greatly reduced. The proposed scheme could achieve the performance closed to the optimal solutions. To the authors' best knowledge, this is the first research work to investigate the IEEE 802.16j multicast and broadcast problem.

Exploring the tolerability of spatiotemporally complex electrical stimulation paradigms

A modified cortical stimulation model was used to investigate the effects of varying the synchronicity and periodicity of electrical stimuli delivered to multiple pairs of electrodes on seizure initiation. In this model, electrical stimulation of the motor cortex of rats, along four pairs of a microwire electrode array, results in an observable seizure with quantifiable electrographic duration and behavioural severity. Periodic stimuli had a constant inter-stimulus intervals across the two-second stimulus duration, whilst synchronous stimuli consisted of singular biphasic, bipolar pulses delivered to the four pairs of electrodes at precisely the same time for the entire two second stimulation period. In this way four combinations of stimulation were possible; periodic/synchronous (P/S), periodic/asynchronous (P/As), aperiodic/synchronous (Ap/S) and aperiodic/asynchronous (Ap/As). All stimulation types were designed with equal pulse width, current intensity and mean frequency of stimulation (60 Hz), standardizing net charge transfer. It was expected that the periodicity of the stimulus would be the primary determinant of seizure initiation and therefore severity and electrographic duration. However, the results showed that significant differences in both severity and duration only occurred when the synchronicity was altered. For periodic stimuli, synchronous delivery increased median seizure duration from 5 s to 13 s and increased median Racine severity from 1 to 3. In the aperiodic case, synchronous stimulus delivery increased median duration from 5.5 s to 11s and resulted in seizures of median severity 3 vs. 0 in the asynchronous case. These findings may have implications for the design of future neurostimulation waveform designs as higher numbers of electrodes and stimulator output channels become available in next generation implants.

Exploring the feasibility of differentiating IEEE 802.15.4 networks to support health-care systems

IEEE 802.15.4 networks are a feasible platform candidate for connecting all health-care-related equipment dispersed across a hospital room to collect critical time-sensitive data about patient health state, such as the heart rate and blood pressure. To meet the quality of service requirements of health-care systems, this paper proposes a multi-priority queue system that differentiates between various types of frames. The effect of the proposed system on the average delay and throughput is explored herein. By employing different contention window parameters, as in IEEE 802.11e, this multi-queue system prioritizes frames on the basis of priority classes. Performance under both saturated and unsaturated traffic conditions was evaluated using a novel analytical model that comprehensively integrates two legacy models for 802.15.4 and 802.11e. To improve the accuracy, our model also accommodates the transmission retries and deferment algorithms that significantly affect the performance of IEEE 802.15.4. The multi-queue scheme is predicted to separate the average delay and throughput of two different classes by up to 48.4 % and 46 %, respectively, without wasting bandwidth. These outcomes imply that the multi-queue system should be employed in health-care systems for prompt allocation of synchronous channels and faster delivery of urgent information. The simulation results validate these model's predictions with a maximum deviation of 7.6%.

Silymarin nanoparticle prevents paracetamol-induced hepatotoxicity

Silymarin (Sm) is a polyphenolic component extracted from Silybum marianum. It is an antioxidant, traditionally used as an immunostimulant, hepatoprotectant, and dietary supplement. Relatively recently, Sm has proved to be a valuable chemopreventive and a useful antineoplastic agent. Medical success for Sm is, however, constrained by very low aqueous solubility and associated biopharmaceutical limitations. Sm flavonolignans are also susceptible to ion-catalyzed degradation in the gut. Proven antihepatotoxic activity of Sm cannot therefore be fully exploited in acute chemical poisoning conditions like that in paracetamol overdose. Moreover, a synchronous delivery that is required for hepatic regeneration is difficult to achieve by itself. This work is meant to circumvent the inherent limitations of Sm through the use of nanotechnology. Sm nanoparticles (Smnps) were prepared by nanoprecipitation in polyvinyl alcohol stabilized Eudragit RS100® polymer (Rohm Pharma GmbH, Darmstadt, Germany). Process parameter optimization provided 67.39% entrapment efficiency and a Gaussian particle distribution of average size 120.37 nm. Sm release from the nanoparticles was considerably sustained for all formulations. Smnps were strongly protective against hepatic damage when tested in a paracetamol overdose hepatotoxicity model. Nanoparticles recorded no animal death even when administered after an established paracetamol-induced hepatic necrosis. Preventing progress of paracetamol hepatic damage was traced for an efficient glutathione regeneration to a level of 11.3 μmol/g in hepatic tissue due to Smnps.

The Status of US Multi-campus Colleges and Schools of Pharmacy

To assess the current status of multi-campus colleges and schools of pharmacy within the United States. Data on multi-campus programs, technology, communication, and opinions regarding benefits and challenges were collected from Web sites, e-mail, and phone interviews from all colleges and schools of pharmacy with students in class on more than 1 campus. Twenty schools and colleges of pharmacy (18 public and 2 private) had multi-campus programs; 16 ran parallel campuses and 4 ran sequential campuses. Most programs used synchronous delivery of classes. The most frequently reported reasons for establishing the multi-campus program were to have access to a hospital and/or medical campus and clinical resources located away from the main campus and to increase class size. Effectiveness of distance education technology was most often sited as a challenge. About 20% of colleges and schools of pharmacy have multi-campus programs most often to facilitate access to clinical resources and to increase class size. These programs expand learning opportunities and face challenges related to technology, resources, and communication.

The Detection and Minimization of Cheating During Concurrent Online Assessments Using Statistical Methods

As distance learning programs in aviation continue to evolve, a natural step in the progression is the fully online assessment of distance students. In some cases, those assessments must occur in synchronous delivery systems, where distance students view lectures and/or take online examinations concurrently. Among the questions that arise in the mind of the aviation educator in such cases are those of how to determine the magnitude of academic dishonesty occurring during concurrent assessments and how to minimize the opportunities of students being assessed to participate in such dishonesty. The author has developed a statistical algorithm to allow the use of common software to detect instances where students pass answers between themselves through various means in order to improve their assessment scores. A study conducted over a period of two semesters during the 2009 – 2010 academic year in two of the author’s distance learning classes indicates the validity of both the algorithm and the methods used to minimize the occurrences of dishonesty.

Synchronous and Asynchronous Distance Delivery Experiences from Two Faculty Members in Special Education at UNC Charlotte

In Special Education at UNC Charlotte, we have been delivering course work in various distance delivery formats (e.g., two-way interactive TV, videoconferencing over the Internet, asynchronous online) for about 15 years. In those years, we have had many opportunities to disseminate our efforts. In this article, we document the experiences of two faculty members, one a more seasoned veteran and one a relatively new faculty member, and discuss our effort to extend the reach of the university to rural North Carolina through distance delivery.

Should we be Allowing Technology to Remove "Distance" from "Distance Education"?

Some researchers suggest that the rapid evolution of increasingly sophisticated e-learning technologies, in combination with synchronous delivery, have resulted in the death of distance education. This paper distinguishes traditional distance education from e-learning, on the basis of geographical separation of teachers and students, no online access requirements, and the historical rationale for distance education. These and other factors, including relative costs, point to longevity, rather than an early demise for this form of distance education. Education for sustainability (EFS) is used as a cautionary case study to illustrate the ways in which e-learning may not adequately serve the goals of EFS as well as traditional distance education. Caution is urged in the further development of e-learning policies to ensure that they distinguish traditional distance education on the basis of its ongoing, special value to learners.

Technology and Tools to Enhance Distributed Engineering Education

While the ongoing information technology (IT) revolution is providing us with tremendous educational opportunities, educators and IT researchers face numerous obstacles and pedagogical questions. The Georgia Institute of Technology (Georgia Tech) has a long history in engineering education research and has developed and designed many different tools for instructor authoring, course capturing, indexing, and retrieval. Special attention has been applied to the design and deployment of distributed learning environments. This paper describes the environment and challenges facing Georgia Tech as it expands its campus worldwide while maintaining integration of faculty and students across these campuses. The focus is primarily on the problems of synchronous delivery to multiple sites with a description of how technology is currently being deployed in Georgia Tech's distance-learning (DL) classrooms, as well as technology that is under development for the DL classroom of the future.

A Multiparty Videoconferencing System Over an Application-Level Multicast Protocol

Increased speeds of PCs and networks have made media communications possible on the Internet. Today, the need for desktop videoconferencing is experiencing robust growth in both business and consumer markets. However, the synchronous delivery of high-volume media content is still a big challenge under a current heterogeneous Internet environment. In this paper, we present a multiparty videoconferencing system based on a peer-to-peer (P2P) solution. The contribution of our paper is twofold. On the one hand, we design an application-level multicast scheme which intends to tolerate the heterogeneity in videoconferencing applications. Design tradeoffs are analyzed and our decisions are made based on extensive experimentation. On the other, we design a five-layer architecture for implementing a multiparty videoconferencing system. This architecture makes a clear-cut distinction between different functional modules and therefore provides rich flexibility in feature adaptation. We believe that our work can be a helpful reference in other efforts on building desktop videoconferencing systems.

Integrating synchronous and asynchronous internet distributed education for maximum effectiveness

Distributed education delivered via the Internet is a growing practice, with most institutions offering at least course websites and many expanding to full course offerings and even online degree progams. There are two schools of thought with regard to delivery mode: the larger group has focused on asynchronous delivery, accessible at any time via webpages and interactive tutorials and quizzes, while a smaller group advocates synchronous delivery where students are online and interact during class time. This paper summarizes the advantages and disadvantages of the two delivery modes and describes our successful and growing experience of more than a decade using an open source synchronous delivery tool blended with a variety of asynchronous capabilities and classroom instruction. We conclude that a synergistic combination of the two modes with in-person instruction, designed to provide maximum flexibility to the student within the constraints of the subject, offers the best support for student learning.

Five Recommendations to Law Schools Offering Legal Instruction Over the Internet

Five Recommendations to Law Schools Offering Legal Instruction over the Internet, addresses the emerging market for legal distance education. The market is being driven by recent changes in ABA regulations, as well as specialization in the curriculum, and expanding costs of traditional education. We are seeing the emergence of legal distance education consortiums, which offer a platform for the trading or selling of courses and programs. However, much skepticism remains about the ability of distance education technology to offer law schools and law students a sufficiently interactive pedagogy. In the words of Supreme Court Justice Ruth Bader Ginsburg legal education is a shared enterprise, a genuine interactive endeavor that . . inevitably looses something vital when students learn in isolation, even if they can engage in virtual interaction with peers and teachers. This paper uses my experience as the Director of the University of Alabama's successful LL.M in Taxation Program to advise law schools how to expand into distance education, while avoiding common pedagogical limitations and administrative problems. The first of five recommendations addresses what to offer and the remaining four offer advice on how to offer distance learning: 1) Offer programs more generously than courses. 2) Collaborate with other schools in offering courses but not when offering programs. 3) Use synchronous delivery of information, like videoconferencing, for the primary mode of instruction. 4) Use asynchronous forms of delivery to increase the level of interaction and support the primary, synchronous form. 5) Use relational marketing to retain and recruit distance education students. In addressing the issue of whether the internet is appropriate for law school instruction, this article contributes to that debate by presenting a model of the right way to offer legal distance education. Until the technology catches up with the traditional classroom, asynchronous forms like web-based discussion boards and streaming video should only be used to supplement a more interactive and synchronous primary mode of instruction like videoconferencing. This article also explains how resolve the potential difficulties that may arise when offering a videoconferencing course or program. The University of Alabama's LL.M. in Tax is a good model for these propositions because it is the only program that I know of which uses over 10 remote classrooms and videoconferencing and asynchronous technologies to create face to face interactions with law students and professors from four different Southeastern states.

Delivery and Expression of Functional Viral RNA Genomes In Planta by Agroinfiltration

Agroinfiltration is a simple, efficient, and powerful approach for transient expression of viral genes as well as DNA-based expression of full-length RNA genomes of plant viruses for studies leading to understanding of replication, movement, and assembly. Most importantly, it results in synchronous delivery of Agrobacterium transformants to a majority of cells encompassing the infiltrated area and is therefore ideal for examining the biological activities of viruses having multipartite genomes. Because of the high transformation rate and efficient accumulation of mRNAs, the method is also ideal for analyzing biological activities of viral genomes with defective replication and cell-to-cell movement characteristics.

Quality-based I/O resource managementfor multimedia document database servers

Slow access to disk-based multimedia data is a major limiting factor in the performance of modern multimedia Web servers connected over broadband networks. The I/O bottleneck becomes even more pronounced for currently evolving systems handling multimedia data, such as audio and video. Retrieval of complex multimedia documents needs to be handled at two levels: I/O bandwidth management for multiple multimedia streams, and interstream and intrastream synchronization for multimedia objects constituting these documents. In this paper, based on the diverse characteristics of multimedia data, we propose efficient techniques for synchronous retrieval and delivery of such data from the storage system to the main memory of the server. We propose methods to quantify user perceived quality via quality-of-presentation (QoP) parameters. We combine QoP and Object Composition Petri Net (OCPN) multimedia data modeling to develop techniques for efficient synchronous retrieval of multimedia data. Since I/O bandwidth is a precious resource, the proposed techniques have low overhead, which is $O(n\log n + mn)$ , where m is the number of logical I/O channels and n is the total number of frames of multimedia data in a scheduling period. We simulate the relative performance of these techniques under diverse I/O conditions and determine the tradeoffs between the system resources, such as memory, bandwidth, and the improvement in QoP for multimedia applications.