Saint Peters College

Englewood Cliffs, NJ, United States

Saint Peters College

Englewood Cliffs, NJ, United States
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Pan J.,Peking University | Sun K.,Peking University | Sun K.,Lan Zhou University | Liang Y.,Peking University | And 8 more authors.
Journal of Endodontics | Year: 2013

Introduction: Complete sterilization of an infected root canal is an important challenge in endodontic treatment. Traditional methods often cannot achieve high-efficiency sterilization because of the complexity of the root canal system. The objective of the study was to investigate in vitro the feasibility of using a cold plasma treatment of a root canal infected with Enterococcus faecalis biofilms. Methods: Seventy single-root teeth infected with E. faecalis biofilms were divided into 7 groups. Group 1 served as the negative control group (no treatment), and group 7 was the positive control group with teeth treated with calcium hydroxide intracanal medication for 7 days. Groups 2 to 6 included teeth treated by cold plasma for 2, 4, 6, 8, and 10 minutes, respectively. The disinfection of the E. faecalis biofilm was evaluated by colony-forming unit (CFU) counting. Scanning electron microscopy was used to evaluate the structural changes of the E. faecalis biofilm before and after plasma treatment. Confocal scanning laser microscopy was used to investigate the vitality of the microorganisms in the biofilm before and after plasma treatment. Results: A significant decrease in the number of CFUs was observed after prolonged cold plasma treatment (based on the statistical analysis of the teeth in groups 2-6). Compared with the positive control group, cold plasma treatment of 8 or 10 minutes (groups 5 and 6) had a significantly higher antimicrobial efficacy (P <.05). The scanning electron microscopic analysis showed that the bacteria membrane was ruptured, and the structure of the biofilm was fully destroyed by the plasma. Confocal scanning laser microscopic studies indicated that the plasma treatment induced E. faecalis death and destruction of the biofilm. Conclusions: The cold plasma had a high efficiency in disinfecting the E. faecalis biofilms in in vitro dental root canal treatment. © 2013 American Association of Endodontists.

Lega L.,Saint PeterS College | Contreras A.H.,Institute Terapia Cognitivo Conductual | Paredes M.T.,Pontifical Xavierian University
Acta Colombiana de Psicologia | Year: 2011

The aim of this study was the adaptation to Colombia of O'Kelly Women's Beliefs Scales (OWBS), an instrument that measures the irrational thinking on the traditional female role. The Colombian version of the scale was prepared using the reverse translation method and administered to 931 women aged between 17 and 70. Exploratory factor analysis with Varimax rotation yielded five factors that accounted for 45.57% of the total variance, based on 37 reactive with factor loadings above. 30. As in previous studies, the existence of a dominant factor that explains 30% of the variance is confirmed. The internal consistency of the scale and the derived factors was adequate, with Cronbach's alpha coefficients between.79 and 94. In general, these results establish equivalence between the Colombian version of the OWBS and the original Australian version. However, given the theoretical foundation of the scale and the magnitude of the correlation between derived factors, a grouping of items in two main factors is proposed- General irrational beliefs about the traditional female role (made up of four derived factors) and Irrational beliefs about the traditional female role in the couple (based on the remaining factor)-. This hypothetical structure should be confirmed empirically in future research.

O'Brien J.L.,Saint Peters College
Nephrology nursing journal : journal of the American Nephrology Nurses' Association | Year: 2011

This study explored relationships among structural empowerment, psychological empowerment, and burnout in registered staff nurses working in outpatient hemodialysis settings. The sample consisted of 233 registered staff nurses. The Emotional Exhaustion Subscale of the Maslach Burnout Inventory, the Conditions for Work Effectiveness II Questionnaire, and Psychological Empowerment Instrument were used to measure variables. Findings indicate that in this population of nurses, there is a significant inverse relationship between structured empowerment and burnout.

Bubka A.,Saint Peters College | Bonatoo F.,Saint Peters College
Perception | Year: 2010

When a large optic-flow pattern is viewed, induced self-motion perception (vection) can result even for observers who are stationary relative to Earth. Vection is common in optokinetic drums, large-screen cinemas, vehicle simulators, and other virtual environments. However, not all optic-flow patterns are equally effective in producing vection. We hypothesized that visual- field characteristics that typically accompany self-motion are likely to facilitate vection. The two characteristics tested in the current study were color and global visual-field movement consistent with head bob and sway that occurs when a person walks or runs. Stationary observers viewed first-person perspective video clips on a rear-projection screen that depicted forward self-motion. Vection onset and magnitude were measured with a computer-interfaced slide device. In experiment 1, either a grayscale or color video was presented. In experiment 2, the video was shot either from a smooth rolling cart or with a hand-held camera that yielded gait information in addition to global expansion. Vection onset was found to be faster, and stronger in magnitude, when videos containing color and gait movements were viewed. These results suggest that visual-field features that are common during actual self-motion can enhance vection in a virtual environment, resulting in a more realistic experience for viewers.

Feng H.,Peking University | Wang R.,Peking University | Sun P.,Peking University | Wu H.,Peking University | And 5 more authors.
Applied Physics Letters | Year: 2010

The mechanisms of eukaryotic cell response to cold plasma are studied. A series of single gene mutants of eukaryotic model organism Saccharomyces cerevisiae are used to compare their sensitivity to plasma treatment with the wild type. We examined 12 mutants in the oxidative stress pathway and the cell cycle pathway, in which 8 are found to be hypersensitive to plasma processing. The mutated genes' roles in the two pathways are analyzed to understand the biological response mechanisms of plasma treatment. The results demonstrate that genes from both pathways are needed for the eukaryotic cells to survive the complex plasma treatment. © 2010 American Institute of Physics.

Kim J.,University of Wollongong | Kim J.,University of Sydney | Palmisano S.,University of Wollongong | Bonato F.,Saint Peters College
Perception | Year: 2012

Research has shown that adding simulated linear head oscillation to radial optic flow displays enhances the illusion of self-motion in depth (ie linear vection). We examined whether this oscillation advantage for vection was due to either the added motion parallax or retinal slip generated by insufficient compensatory eye movement during display oscillation. We constructed radial flow displays which simulated 1 Hz horizontal linear head oscillation (generates motion parallax) or angular head oscillation in yaw (generates no motion parallax).We found that adding simulated angular or linear head oscillation to radial flow increased the strength of linear vection in depth. Neither type of simulated head oscillation significantly reduced vection onset latencies relative to pure radial flow. Simultaneous eye-movement recordings showed that slow-phase ocular following responses (OFRs) were induced in both linear and angular viewpoint oscillation condi- tions. Vection strength was significantly reduced by active central fixation when viewing displays which simulated angular, but not linear, head oscillation. When these displays with angular oscillation were viewed without stable fixation, vection strength was found to increase with the velocity and regularity of the OFR.We conclude that vection improvements observed during central viewing of displays with angular viewpoint oscillation depend on the generation of eye movements. © 2012 a Pion publication.

Schoenbach K.H.,Old Dominion University | Zhu W.,Saint Peters College
IEEE Journal of Quantum Electronics | Year: 2012

Spatially confined plasmas with dimensions in the submillimeter range have been found to be stable at atmospheric pressure. These microplasmas are nonequilibrium plasmas with an electron energy distribution which contains a significant fraction of high energy electrons. This favors, in combination with the high gas density, the formation of excimers. The possibility for operating these discharges in parallel, or expanding the nonequilibrium plasma two-dimensionally on a flat cathode allows for extended area light-sources, including excimer lamps. The spectral range of these lamps reaches from the visible into the vacuum ultraviolet, down to wavelengths of 75 nm for helium excimer radiation. Highest efficiencies of 6-9% were obtained for xenon excimers when the discharge was operated dc, and 20% when operated in a nanosecond pulsed mode. Besides excimer radiation, microdischarges have also been shown to emit intense line radiation in the vacuum ultraviolet when noble gases with small admixtures of hydrogen and oxygen were used. In this paper, we discuss basic properties of several types of high-pressure microplasmas, focusing on their dc and pulsed dc operation, followed by an overview of the experimental and modeling results relevant for their use as ultraviolet light sources. The prospect of developing microplasma lamps by forming arrays of microdischarges and possibly excimer lasers by operating microdischarges in series is briefly discussed. © 2012 IEEE.

Sun P.,Peking University | Wu H.,Peking University | Bai N.,Peking University | Bai N.,University of Sichuan | And 7 more authors.
Plasma Processes and Polymers | Year: 2012

Bacillus subtilis spores suspended in distilled water was effectively inactivated in 6 min by a direct-current atmospheric pressure non-thermal air plasma microjet. Scanning electron microscopic images show clear distortion and debris of spores after plasma treatment. Direct contribution by temperature and pH change of water as well as relatively long lived species in plasma activated water (PAW) is excluded. Short lived species (such as ·OH, ·O 2- and O 2( 1Δ g)) are detected in the plasma-water system by electron spin resonance spectroscopy, and are considered to be the most important agents in the inactivation process. B. subtilis spores in water were effectively inactivated in 6 min by a DC air plasma microjet. SEM images show clear distortion and debris of spores after plasma treatment. Short lived species (such as ·OH, ·O 2- and O 2( 1Δ g)) are detected in the plasma-water system by ESR spectroscopy, and are considered to be the most important agents in the inactivation process. Direct contribution from temperature, pH and long lived species are excluded. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ma R.,Peking University | Feng H.,Peking University | Li F.,Peking University | Liang Y.,Peking University | And 5 more authors.
Applied Physics Letters | Year: 2012

With the development of plasma medicine, safety issues are emerging as a serious concern. In this study, both intracellular (genetic engineering) and extracellular (scavengers) measures were tested in an effort to determine the best protection for cells against plasma-induced oxidative stress. All results of immediate reactive species detection, short term survival and long term proliferation, suggest that intracellular pathways are superior in reducing oxidative stress and cell death. This work provides a potential mechanism to enhance safety and identifies precautionary measures that should be taken in future clinical applications of plasmas. © 2012 American Institute of Physics.

Agency: NSF | Branch: Standard Grant | Program: | Phase: | Award Amount: 10.00K | Year: 2010

This grant will provide partial support for American graduate and postdoctoral students to participate in an international 2nd Graduate Summer Institute on Complex Plasmas, which will be held from August 4 to August 14, 2010 at the University of Greifswald in Greifswald, Germany. The stated goal is educational advancement of the scientific challenges and technological opportunities afforded by complex plasmas.

The summer school will treat dusty and strongly coupled plasmas, reactive plasmas, microplasmas, quantum plasmas, and plasmas in contact with surfaces. This broad yet rigorous curriculum will lead to further advancement in this new and emerging field by attracting young American researchers in significant numbers since they will encounter scientific challenges as well as technological opportunities in these areas upon which they can build a successful academic or industrial careers. Further, the emerging complex plasma applications appear to be a remarkable fertile field for small, high-tech start-up companies which will perceive this field as a favorable innovation source for marketplace realization of basic plasma concepts.

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