34 results
Neurodevelopmental outcomes at 18 months of children diagnosed with CHD compared to children born very preterm
- Samantha D. Roberts, Renee Sananes, Magdalena Wojtowicz, Michael Seed, Steven P. Miller, Vann Chau, Stephanie H. Au-Young, Ting Guo, Linh Ly, Vanna Kazazian, Ruth E. Grunau, Tricia S. Williams
-
- Journal:
- Cardiology in the Young , First View
- Published online by Cambridge University Press:
- 02 January 2024, pp. 1-7
-
- Article
-
- You have access Access
- Open access
- HTML
- Export citation
-
Children with CHD or born very preterm are at risk for brain dysmaturation and poor neurodevelopmental outcomes. Yet, studies have primarily investigated neurodevelopmental outcomes of these groups separately.
Objective:To compare neurodevelopmental outcomes and parent behaviour ratings of children born term with CHD to children born very preterm.
Methods:A clinical research sample of 181 children (CHD [n = 81]; very preterm [≤32 weeks; n = 100]) was assessed at 18 months.
Results:Children with CHD and born very preterm did not differ on Bayley-III cognitive, language, or motor composite scores, or on expressive or receptive language, or on fine motor scaled scores. Children with CHD had lower ross motor scaled scores compared to children born very preterm (p = 0.047). More children with CHD had impaired scores (<70 SS) on language composite (17%), expressive language (16%), and gross motor (14%) indices compared to children born very preterm (6%; 7%; 3%; ps < 0.05). No group differences were found on behaviours rated by parents on the Child Behaviour Checklist (1.5–5 years) or the proportion of children with scores above the clinical cutoff. English as a first language was associated with higher cognitive (p = 0.004) and language composite scores (p < 0.001). Lower median household income and English as a second language were associated with higher total behaviour problems (ps < 0.05).
Conclusions:Children with CHD were more likely to display language and motor impairment compared to children born very preterm at 18 months. Outcomes were associated with language spoken in the home and household income.
Effectiveness of a neonatal intensive care unit–specific antimicrobial stewardship program: A ten-year review
- Katrina H. Assen, Vanessa Paquette, Arianne Y. Albert, Ginger Shi, Jocelyn A. Srigley, Horacio Osiovich, Ashley D. Roberts, Joseph Y. Ting
-
- Journal:
- Infection Control & Hospital Epidemiology / Volume 44 / Issue 11 / November 2023
- Published online by Cambridge University Press:
- 03 February 2023, pp. 1718-1724
- Print publication:
- November 2023
-
- Article
- Export citation
-
Objective:
To evaluate the change in consumption of specific antibiotics in a neonatal intensive care unit after the implementation of an antimicrobial stewardship program (ASP).
Design:Retrospective cohort study between January 1, 2010, and December 31,2019.
Setting:The neonatal intensive care unit at British Columbia Women’s Hospital (Vancouver Canada), a tertiary-care center.
Patients:Admitted neonates prescribed antibiotics.
Methods:We implemented an ASP with an early implementation phase starting in January 2014 (period 2) and a later phase starting in January 2017 (period 3). Patient demographics were collected, including birth weight, gestational age, history of necrotizing enterocolitis (NEC), and surgical operations from existing databases. Interrupted time-series analysis was used, and comparison of antibiotic days of therapy (DOT) averages were conducted across the preimplementation period (period 1), period 2, and period 3 regarding total patients and subgroups.
Results:We identified 4,512 infants. There was a significant decrease in DOT from 472 (95% confidence interval [CI], 431–517) in period 1 to 405 (95% CI, 367–446) in period 2 to 313 (95% CI, 280–350) in period 3. We detected a significant decrease in the use of ampicillin, aminoglycosides, cloxacillin, and linezolid but not in vancomycin or cefotaxime. Subgroup analyses of infants <1,500 g and those without NEC or surgery showed decreases in the use of cloxacillin, aminoglycosides, and linezolid.
Conclusions:The implementation of an ASP was associated with a significant decrease in the overall DOT and use of certain antibiotics. This study presents important targets for ongoing ASP work.
Providing safe care for patients in the coronavirus disease 2019 (COVID-19) era: A case series evaluating risk for hospital-associated COVID-19
- Part of
- Elizabeth B. Habermann, Aaron J. Tande, Benjamin D. Pollock, Matthew R. Neville, Henry H. Ting, Priya Sampathkumar
-
- Journal:
- Infection Control & Hospital Epidemiology / Volume 42 / Issue 12 / December 2021
- Published online by Cambridge University Press:
- 05 April 2021, pp. 1479-1485
- Print publication:
- December 2021
-
- Article
-
- You have access Access
- Open access
- HTML
- Export citation
-
Objective:
We evaluated the risk of patients contracting coronavirus disease 2019 (COVID-19) during their hospital stay to inform the safety of hospitalization for a non–COVID-19 indication during this pandemic.
Methods:A case series of adult patients hospitalized for 2 or more nights from May 15 to June 15, 2020 at large tertiary-care hospital in the midwestern United States was reviewed. All patients were screened at admission with the severe acute respiratory coronavirus virus 2 (SARS-CoV-2) polymerase chain reaction (PCR) test. Selected adult patients were also tested by IgG serology. After dismissal, patients with negative serology and PCR at admission were asked to undergo repeat serologic testing at 14–21 days after discharge. The primary outcome was healthcare-associated COVID-19 defined as a new positive SARS-CoV-2 PCR test on or after day 4 of hospital stay or within 7 days of hospital dismissal, or seroconversion in patients previously established as seronegative.
Results:Of the 2,068 eligible adult patients, 1,778 (86.0%) completed admission PCR testing, while 1,339 (64.7%) also completed admission serology testing. Of the 1,310 (97.8%) who were both PCR and seronegative, 445 (34.0%) repeated postdischarge serology testing. No healthcare-associated COVID-19 cases were detected during the study period. Of 1,310 eligible PCR and seronegative adults, no patients tested PCR positive during hospital admission (95% confidence interval [CI], 0.0%–0.3%). Of the 445 (34.0%) who completed postdischarge serology testing, no patients seroconverted (0.0%; 95% CI, 0.0%–0.9%).
Conclusion:We found low likelihood of hospital-associated COVID-19 with strict adherence to universal masking, physical distancing, and hand hygiene along with limited visitors and screening of admissions with PCR.
P018: Journal club functions as a community of practice that safeguards quality assurance in the era of free open access medical education: a qualitative study
- D. Ting, B. Bailey, F. Scheuermeyer, T. Chan, D. Harris
-
- Journal:
- Canadian Journal of Emergency Medicine / Volume 22 / Issue S1 / May 2020
- Published online by Cambridge University Press:
- 13 May 2020, pp. S70-S71
- Print publication:
- May 2020
-
- Article
-
- You have access Access
- Export citation
-
Introduction: The ways in which Emergency Medicine (EM) physicians interact with the medical literature has been transformed with the rise of Free Open Access Medical Education (FOAM). Although nearly all residents use FOAM resources, some criticize the lack of universal quality assurance. This problem is a particular risk for trainees who have many time constraints and incompletely developed critical appraisal skills. One potential safeguard is journal club, which is used by virtually all EM residency programs in North America to review new literature. However, EM resident perspectives have not been studied. Our research objective was to describe how residents perceive journal club to influence how they translate the medical literature into their clinical practice. Our research question was whether FOAM has influenced residents’ goals and perceived value of journal club. Methods: We developed a semi-structured interview script in conjunction with a methods expert and refined it via pilot testing. Following constructivist grounded theory, and using both purposive and theoretical sampling, we conducted a focus group (n = 7) and 18 individual interviews with EM residents at the 4 training sites of the University of British Columbia. In total, we analyzed 920 minutes of recorded audio. Two authors independently coded each transcript, with discrepancies reconciled by discussion and consensus. Constant comparative analysis was performed. We conducted return of findings through public presentations. Results: We found evidence that journal club works as a community of practice with a progression of roles from junior to senior residents. Participants described journal club as a safe venue to compare practice patterns and to gain insight into the practical wisdom of their peers and mentors. The social and academic activities present at journal club interacted positively to foster this environment. In asking residents about ways that journal club accelerates knowledge translation, we actually found that residents cite journal club as a quality check to prevent premature adoption of new research findings. Residents are hesitant to adopt new literature into their practice without positive validation, which can occur during journal club. Conclusion: Journal club functions as a community of practice that is valued by residents. Journal club is a primary way that new evidence can be validated before being put into practice, and may act as quality assurance in the era of FOAM.
Oocyte exposure to supraphysiological estradiol during ovarian stimulation increased the risk of adverse perinatal outcomes after frozen-thawed embryo transfer: a retrospective cohort study
- Chen-Chi Duan, Cheng Li, Yi-Chen He, Jing-Jing Xu, Chao-Yi Shi, Hong-Tao Hu, Yun-Fei Su, Lei Chen, Ya-Jing Tan, Zhi-Wei Liu, Jian-Zhong Sheng, William D. Fraser, Yan-Ting Wu, He-Feng Huang
-
- Journal:
- Journal of Developmental Origins of Health and Disease / Volume 11 / Issue 4 / August 2020
- Published online by Cambridge University Press:
- 04 November 2019, pp. 392-402
-
- Article
-
- You have access Access
- Open access
- HTML
- Export citation
-
Maternal supraphysiological estradiol (E2) environment during pregnancy leads to adverse perinatal outcomes. However, the influence of oocyte exposure to high E2 levels on perinatal outcomes remains unknown. Thus, a retrospective cohort study was conducted to explore the effect of high E2 level induced by controlled ovarian stimulation (COH) on further outcomes after frozen embryo transfer (FET). The study included all FET cycles (n = 10,581) between 2014 and 2017. All cycles were categorized into three groups according to the E2 level on the day of the human Chorionic Gonadotropin trigger. Odds ratios (ORs) and their confidence intervals (CIs) were calculated to evaluate the association between E2 level during COH and pregnancy outcomes and subsequent neonatal outcomes. From our findings, higher E2 level was associated with lower percentage of chemical pregnancy, clinical pregnancy, ongoing pregnancy, and live birth as well as increased frequency of early miscarriage. Preterm births were more common among singletons in women with higher E2 level during COH (aOR1 = 1.93, 95% CI: 1.22–3.06; aOR2 = 2.05, 95% CI: 1.33–3.06). Incidence of small for gestational age (SGA) was more common in both singletons (aOR1 = 2.01, 95% CI: 1.30–3.11; aOR2 = 2.51, 95% CI: 1.69–3.74) and multiples (aOR1 = 1.58, 95% CI: 1.03–2.45; aOR2 = 1.99, 95% CI: 1.05–3.84) among women with relatively higher E2 level. No association was found between high E2 level during COH and the percentage of macrosomia or large for gestational age. In summary, oocyte exposure to high E2 level during COH should be brought to our attention, since the pregnancy rate decreasing and the risk of preterm birth and SGA increasing following FET.
Coping With a Mass Casualty: Insights into a Hospital’s Emergency Response and Adaptations After the Formosa Fun Coast Dust Explosion
- Sheuwen Chuang, David D. Woods, Hsien-Wei Ting, Richard I. Cook, Jiin-Chyr Hsu
-
- Journal:
- Disaster Medicine and Public Health Preparedness / Volume 14 / Issue 4 / August 2020
- Published online by Cambridge University Press:
- 23 August 2019, pp. 467-476
-
- Article
- Export citation
-
Objective:
The study provides a comprehensive insight into how an initial receiving hospital without adequate capacity adapted to coping with a mass casualty incident after the Formosa Fun Coast Dust Explosion (FFCDE).
Methods:Data collection was via in-depth interviews with 11 key participants. This was combined with information from medical records of FFCDE patients and admission logs from the emergency department (ED) to build a detailed timeline of patients flow and ED workload changes. Process tracing analysis focused on how the ED and other units adapted to coping with the difficulties created by the patient surge.
Results:The hospital treated 30 victims with 36.3% average total body surface area burn for over 5 hours alongside 35 non-FFCDE patients. Overwhelming demand resulted in the saturation of ED space and intensive care unit beds, exhaustion of critical materials, and near-saturation of clinicians. The hospital reconfigured human and physical resources differently from conventional drills. Graphical timelines illustrate anticipatory or reactive adaptations. The hospital’s ability to adapt was based on anticipation during uncertainty and coordination across roles and units to keep pace with varying demands.
Conclusion:Adapting to beyond-surge capacity incident is essential to effective disaster response. Building organizational support for effective adaptation is critical for disaster planning.
P150: Emergency medicine resident perspectives on journal club as a community of practice and its impact on clinical medicine
- D. K. Ting, B. Bailey, F. Scheuermeyer, T. M. Chan, D. R. Harris
-
- Journal:
- Canadian Journal of Emergency Medicine / Volume 20 / Issue S1 / May 2018
- Published online by Cambridge University Press:
- 11 May 2018, p. S110
- Print publication:
- May 2018
-
- Article
-
- You have access Access
- Export citation
-
Introduction: Despite revolutionary changes in the medical education landscape, journal club (JC) continues to be a ubiquitous pedagogical tool and is a primary way that residency programs review new evidence and teach evidence-based medicine. JC is a community of practice among physicians, which may help translate research findings into practice. Program representatives state that JC should have a goal of translating novel research into changes in clinical care, but there has been minimal evaluation of the success of JC in achieving this goal. Specifically, emergency medicine resident perspectives on the utility of JC remain unknown. Methods: We designed a multi-centre qualitative study for three distinct academic environments at the University of British Columbia (Vancouver, Victoria and Kelowna). Pilot testing was performed to generate preliminary themes and to finalize the interview script. An exploratory, semi-structured focus group was performed, followed by multiple one-on-one interviews using snowball sampling. Iterative thematic analysis directed data collection until thematic sufficiency was achieved. Analysis was conducted using a constructivist Grounded Theory method with communities of practice as a theoretical lens. Themes were compared to the existing literature to corroborate or challenge existing educational theory. Results: Pilot testing has revealed the following primary themes: (1) Only select residents are able to increase their participation in JC over the course of residency and navigate the transition from peripheral participant to core member; (2) These residents use their increased clinical experience to perceive relevance in JC topics, and; (3) Residents who remain peripheral participants identify a lack time to prepare for journal club and a lack of staff physician attendance as barriers to resident engagement. We will further develop these themes during the focus group and interview phases of our study. Conclusion: JC is a potentially valuable educational resource for residents. JC works as a community of practice only for a select group of residents, and many remain peripheral participants for the duration of their residency. Incorporation of Free Open-Access Medical Education resources may also decrease preparation time for residents and staff physicians and increase buy-in. To augment clinical impact, the JC community of practice may need to expand beyond emergency medicine and include other specialties.
LO12: Implementation of an editorial internship at the Canadian Journal of Emergency Medicine to foster education and participation in academic emergency medicine
- D. K. Ting, R. B. Abu-Laban, L. Morrison, J. Ducharme, E. S. Lang
-
- Journal:
- Canadian Journal of Emergency Medicine / Volume 20 / Issue S1 / May 2018
- Published online by Cambridge University Press:
- 11 May 2018, pp. S10-S11
- Print publication:
- May 2018
-
- Article
-
- You have access Access
- Export citation
-
Introduction: Medical journals are an essential venue for knowledge translation. Skilled reviewers and editors are required to ensure quality standards in research publications and yet postgraduate programs rarely include this training in their curricula. Imparting appropriate skills and developing capacity in journalship has thus proved challenging. The Canadian Journal of Emergency Medicine (CJEM) is the national journal for Emergency Medicine (EM) in Canada. The CJEM editorial board recently decided to provide longitudinal mentorship for junior academic faculty members and trainees through an editorial internship. The internship had three goals for participants: (1) introduce and develop the responsibilities and skills of a good editor; (2) enhance a career in academic EM; and, (3) galvanize future participation as a reviewer or editor in scientific publications. Methods: The senior editorial board of CJEM and the inaugural intern developed a one-year Editorial Internship that was launched in June 2017. The curricular framework was designed by current and prior CJEM senior editors from four Canadian universities, and was informed by similar programs in the United States. The curriculum was refined iteratively based on feedback and discussion between the senior editors and intern. The internship was designed for a single individual in the Canadian EM community, including residents, pediatric fellows and practicing emergency physicians. Results: To develop the responsibilities and skills of being a good editor, the intern performed six mentored reviews of manuscripts either under current review at CJEM or previous submissions identified as difficult peer review decisions. In addition, the intern learned about CJEM values and norms by participating in monthly videoconference meetings and quarterly editorial board meetings. To enhance an academic career, the intern was assigned two writing projects under the guidance of senior editors for publication in CJEM, and completed an online critical appraisal course. Conclusion: The inaugural editorial intern gained experience as an editor and produced scholarly work. We feel the internship met its first two goals, and CJEM has committed to continue the internship annually. The ultimate determination of whether the internship achieved its third goal will only be known after longitudinal tracking of participants career involvement in academic publishing and editing.
Defining CT Perfusion Thresholds for Infarction in the Golden Hour and With Ultra-Early Reperfusion
- Mohamed Najm, Fahad S. Al-Ajlan, Mari E. Boesen, Lisa Hur, Chi Kyung Kim, Enrico Fainardi, Michael D. Hill, Andrew M. Demchuk, Mayank Goyal, Ting Y. Lee, Bijoy K. Menon
-
- Journal:
- Canadian Journal of Neurological Sciences / Volume 45 / Issue 3 / May 2018
- Published online by Cambridge University Press:
- 19 February 2018, pp. 339-342
-
- Article
-
- You have access Access
- HTML
- Export citation
-
In this brief report, computed tomography perfusion (CTP) thresholds predicting follow-up infarction in patients presenting <3 hours from stroke onset and achieving ultra-early reperfusion (<45 minutes from CTP) are reported. CTP thresholds that predict follow-up infarction vary based on time to reperfusion: Tmax >20 to 23 seconds and cerebral blood flow <5 to 7 ml/min−1/(100 g)−1 or relative cerebral blood flow <0.14 to 0.20 optimally predicted the final infarct. These thresholds are stricter than published thresholds.
Stretchable bioelectronics—Current and future
- Ishan D. Joshipura, Mickey Finn III, Siew Ting Melissa Tan, Michael D. Dickey, Darren J. Lipomi
-
- Journal:
- MRS Bulletin / Volume 42 / Issue 12 / December 2017
- Published online by Cambridge University Press:
- 08 December 2017, pp. 960-967
- Print publication:
- December 2017
-
- Article
- Export citation
-
Materials used in wearable and implantable electronic devices should match the mechanical properties of biological tissues, which are inherently soft and deformable. In comparison to conventional rigid electronics, soft bioelectronics can provide accurate and real-time monitoring of physiological signals, improve comfort, and enable altogether new modalities for sensing. This article highlights recent progress, identifies technical challenges, and offers possible solutions for the emerging field of stretchable bioelectronics. We organize the content into three topical categories: (1) biological integration of soft electronic materials, (2) materials and mechanics, and (3) soft robotics. Finally, we conclude this article with a discussion on the outlook of the field and future challenges.
P014: Palliative and end of life care education in Canadian emergency medicine residency programs: a national cross-sectional survey
- J. Baylis, D.R. Harris, C. Chen, D.K. Ting, A. Kwan, K. Clark, D. Williscroft
-
- Journal:
- Canadian Journal of Emergency Medicine / Volume 19 / Issue S1 / May 2017
- Published online by Cambridge University Press:
- 15 May 2017, p. S82
- Print publication:
- May 2017
-
- Article
-
- You have access Access
- Export citation
-
Introduction: Palliative care is a broad approach to care for patients with serious or life-threatening illnesses. This includes relief of symptoms, such as pain, that interfere with a patient’s quality of life. It therefore falls firmly within the realm of emergency medicine (EM). 94% of emergency physicians report a need for education in dealing with death and dying. Nevertheless, there are no generally agreed upon competencies for Canadian EM residents with regard to palliative care and end of life care in the emergency department (ED). We performed a cross-sectional study of Canadian EM residency programs to measure the existing curricula in palliative and end of life care. Our primary outcome was the prevalence of structured educational programs for palliative and end of life care. Methods: An e-survey was e-mailed to all program directors of both CCFP(EM) and EM post-graduate training programs countrywide, using FluidSurveysTM. It included questions regarding current palliative and end of life care curricula from formal rotations to seminars and online modules. The survey was developed in consultation with the author group including specialists in education, palliative care medicine, emergency medicine, and medical education. Hired translators were employed to include French speaking programs in Canada. This study had ethical approval: Interior Health REB and UBC CREB certificate 2016-17-026-H. Results: The survey was open from October 12th to December 19th, 2016. During that time, we received 26 responses including 5 French speaking programs, for a response rate of 72.2%. The primary outcome was present in 38.5% of programs. There was no difference between FRCP and CCFP(EM) programs in the occurrence of the primary outcome (p=1; Fisher’s Exact Text). However, CCFP(EM) program directors commented that many of their residents had completed palliative care rotations in their family medicine training. The largest barriers to education included time (84.6%), curriculum development (80.8%), and availability of instructors (50.0%). Conclusion: Our preliminary analysis shows that few Canadian post-graduate EM programs have a structured educational program pertaining to palliative and end of life care. Current barriers to education that can be addressed in future curricular initiatives include lack of time, curriculum development, and instructor availability.
Long-Term Carriage of Ciprofloxacin-Resistant Escherichia coli Isolates in High-Risk Nursing Home Residents
- Miriam D. Ismail, Ting Luo, Sara McNamara, Bonnie Lansing, Evonne Koo, Lona Mody, Betsy Foxman
-
- Journal:
- Infection Control & Hospital Epidemiology / Volume 37 / Issue 4 / April 2016
- Published online by Cambridge University Press:
- 19 January 2016, pp. 440-447
- Print publication:
- April 2016
-
- Article
- Export citation
-
BACKGROUND
Rates of multidrug-resistant gram-negative organisms are surpassing those of methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci in nursing homes (NHs).
OBJECTIVETo characterize the incidence and duration of carriage of ciprofloxacin-resistant Escherichia coli (CipREc) in NHs and identify those in the O25b-ST131 lineage.
METHODSWe collected 227 CipREc isolates obtained by routine and regular surveillance of high-risk NH residents with indwelling devices. Repetitive element palindromic (REP)–polymerase chain reaction assay and multiplex polymerase chain reaction amplification for O25b-ST131 E. coli detection were performed using (GTG)5-primers and O25pabBspe and trpA2 primer pairs, respectively.
RESULTSWe found a high period prevalence of CipREc colonization (21.5%), high rates of recolonization with the same strain following clearing (0.46 recolonizations/ person/ year), and an acquisition incidence of 1.05 cases/1,000 person-days. Almost three-quarters of colonized residents carried strains in the O25b-ST131 E. coli lineage. Compared with isolates not in the lineage, O25b-ST131 isolates were carried significantly longer (10 vs 3 months). We identified 18 different REP-types; 2 occurred in 55% of the residents colonized with CipREc, and in more than 1 NH. Duration of CipREc carriage varied by REP-type and averaged 6 months.
CONCLUSIONCipREc occurred frequently in NH residents and is carried for long durations, and reacquisition following clearance is common
Trial registration. ClinicalTrials.gov identifier: NCT01062841.
Infect. Control Hosp. Epidemiol. 2016;37(4):440–447
A balloon bursting underwater
- A. R. Vasel-Be-Hagh, R. Carriveau, D. S.-K. Ting
-
- Journal:
- Journal of Fluid Mechanics / Volume 769 / 25 April 2015
- Published online by Cambridge University Press:
- 25 March 2015, pp. 522-540
-
- Article
- Export citation
-
A buoyant vortex ring produced by an underwater bursting balloon was studied experimentally. The effect of dimensionless surface tension on characteristics including rise velocity, rate of expansion, circulation, trajectory, and lifetime of the vortex ring bubble was investigated. Results showed reasonable agreement with the literature on vortex rings produced by conventional approaches. It was observed that as the dimensionless surface tension increased, the rise velocity, the circulation and consequently the stability of the vortex ring bubble increased; however, the rate of expansion tends toward constant values. A semi-analytical model is proposed by modifying the drag-based model presented by Sullivan et al. (J. Fluid Mech., vol. 609, 2008, pp. 319–347) to make it applicable to buoyant vortex rings. The modified model suggests that the vortex ring expansion is essentially due to the buoyancy force. An expression is also derived for the circulation in terms of the initial volume of the balloon and the depth at which the balloon bursts.
Eliminating Central Line–Associated Bloodstream Infections: A National Patient Safety Imperative
- Sean M. Berenholtz, Lisa H. Lubomski, Kristina Weeks, Christine A. Goeschel, Jill A. Marsteller, Julius C. Pham, Melinda D. Sawyer, David A. Thompson, Bradford D. Winters, Sara E. Cosgrove, Ting Yang, Thomas A. Louis, Barbara Meyer Lucas, Christine T. George, Sam R. Watson, Mariana I. Albert-Lesher, Justin R. St. Andre, John R. Combes, Deborah Bohr, Stephen C. Hines, James B. Battles, Peter J. Pronovost, on behalf of the On the CUSP: Stop BSI programa
-
- Journal:
- Infection Control & Hospital Epidemiology / Volume 35 / Issue 1 / January 2014
- Published online by Cambridge University Press:
- 10 May 2016, pp. 56-62
- Print publication:
- January 2014
-
- Article
- Export citation
-
Background.
Several studies demonstrating that central line–associated bloodstream infections (CLABSIs) are preventable prompted a national initiative to reduce the incidence of these infections.
Methods.We conducted a collaborative cohort study to evaluate the impact of the national “On the CUSP: Stop BSI” program on CLABSI rates among participating adult intensive care units (ICUs). The program goal was to achieve a unit-level mean CLABSI rate of less than 1 case per 1,000 catheter-days using standardized definitions from the National Healthcare Safety Network. Multilevel Poisson regression modeling compared infection rates before, during, and up to 18 months after the intervention was implemented.
Results.A total of 1,071 ICUs from 44 states, the District of Columbia, and Puerto Rico, reporting 27,153 ICU-months and 4,454,324 catheter-days of data, were included in the analysis. The overall mean CLABSI rate significantly decreased from 1.96 cases per 1,000 catheter-days at baseline to 1.15 at 16–18 months after implementation. CLABSI rates decreased during all observation periods compared with baseline, with adjusted incidence rate ratios steadily decreasing to 0.57 (95% confidence intervals, 0.50–0.65) at 16–18 months after implementation.
Conclusion.Coincident with the implementation of the national “On the CUSP: Stop BSI” program was a significant and sustained decrease in CLABSIs among a large and diverse cohort of ICUs, demonstrating an overall 43% decrease and suggesting the majority of ICUs in the United States can achieve additional reductions in CLABSI rates.
New Fossil Turtle Material from the Hemphillian Pascagoula Formation of Southeast Louisiana
- Ian M. Cannon, Judith A. Schiebout, Suyin D. Ting
-
- Journal:
- The Paleontological Society Special Publications / Volume 13 / 2014
- Published online by Cambridge University Press:
- 26 July 2017, p. 31
- Print publication:
- 2014
-
- Article
- Export citation
A detailed look at chemical abundances in the Magellanic Clouds
- Richard A. Shaw, Ting-Hui Lee, Letizia Stanghellini, James E. Davies, D. Anibal García-Hernández, Pedro García-Lario, Jose-Vicente Perea-Calderón, Eva Villaver, Arturo Manchado, Stacy Palen, Bruce Balick
-
- Journal:
- Proceedings of the International Astronomical Union / Volume 7 / Issue S283 / July 2011
- Published online by Cambridge University Press:
- 30 August 2012, pp. 502-503
- Print publication:
- July 2011
-
- Article
-
- You have access Access
- Export citation
-
We determine elemental abundances of He, N, O, Ne, S, and Ar in Magellanic Cloud planetary nebulae (PNe) using direct methods and a large set of observed ions, minimizing the need for ionization correction factors. In contrast to prior studies, we find a clear separation between Type I and non-Type I PNe in these low-metallicity environments, and no evidence that the O-N nucleosynthesis cycle is active in low-mass progenitors. We find that the S/O abundance ratio is anomalously low compared to H ii regions, confirming the “sulfur anomaly” found for Galactic PNe. We also found that Ne/O is elevated in some cases, raising the possibility that Ne yields in low-mass AGB stars may be enhanced at low metallicity.
Contributors
-
- By Rose Teteki Abbey, K. C. Abraham, David Tuesday Adamo, LeRoy H. Aden, Efrain Agosto, Victor Aguilan, Gillian T. W. Ahlgren, Charanjit Kaur AjitSingh, Dorothy B E A Akoto, Giuseppe Alberigo, Daniel E. Albrecht, Ruth Albrecht, Daniel O. Aleshire, Urs Altermatt, Anand Amaladass, Michael Amaladoss, James N. Amanze, Lesley G. Anderson, Thomas C. Anderson, Victor Anderson, Hope S. Antone, María Pilar Aquino, Paula Arai, Victorio Araya Guillén, S. Wesley Ariarajah, Ellen T. Armour, Brett Gregory Armstrong, Atsuhiro Asano, Naim Stifan Ateek, Mahmoud Ayoub, John Alembillah Azumah, Mercedes L. García Bachmann, Irena Backus, J. Wayne Baker, Mieke Bal, Lewis V. Baldwin, William Barbieri, António Barbosa da Silva, David Basinger, Bolaji Olukemi Bateye, Oswald Bayer, Daniel H. Bays, Rosalie Beck, Nancy Elizabeth Bedford, Guy-Thomas Bedouelle, Chorbishop Seely Beggiani, Wolfgang Behringer, Christopher M. Bellitto, Byard Bennett, Harold V. Bennett, Teresa Berger, Miguel A. Bernad, Henley Bernard, Alan E. Bernstein, Jon L. Berquist, Johannes Beutler, Ana María Bidegain, Matthew P. Binkewicz, Jennifer Bird, Joseph Blenkinsopp, Dmytro Bondarenko, Paulo Bonfatti, Riet en Pim Bons-Storm, Jessica A. Boon, Marcus J. Borg, Mark Bosco, Peter C. Bouteneff, François Bovon, William D. Bowman, Paul S. Boyer, David Brakke, Richard E. Brantley, Marcus Braybrooke, Ian Breward, Ênio José da Costa Brito, Jewel Spears Brooker, Johannes Brosseder, Nicholas Canfield Read Brown, Robert F. Brown, Pamela K. Brubaker, Walter Brueggemann, Bishop Colin O. Buchanan, Stanley M. Burgess, Amy Nelson Burnett, J. Patout Burns, David B. Burrell, David Buttrick, James P. Byrd, Lavinia Byrne, Gerado Caetano, Marcos Caldas, Alkiviadis Calivas, William J. Callahan, Salvatore Calomino, Euan K. Cameron, William S. Campbell, Marcelo Ayres Camurça, Daniel F. Caner, Paul E. Capetz, Carlos F. Cardoza-Orlandi, Patrick W. Carey, Barbara Carvill, Hal Cauthron, Subhadra Mitra Channa, Mark D. Chapman, James H. Charlesworth, Kenneth R. Chase, Chen Zemin, Luciano Chianeque, Philip Chia Phin Yin, Francisca H. Chimhanda, Daniel Chiquete, John T. Chirban, Soobin Choi, Robert Choquette, Mita Choudhury, Gerald Christianson, John Chryssavgis, Sejong Chun, Esther Chung-Kim, Charles M. A. Clark, Elizabeth A. Clark, Sathianathan Clarke, Fred Cloud, John B. Cobb, W. Owen Cole, John A Coleman, John J. Collins, Sylvia Collins-Mayo, Paul K. Conkin, Beth A. Conklin, Sean Connolly, Demetrios J. Constantelos, Michael A. Conway, Paula M. Cooey, Austin Cooper, Michael L. Cooper-White, Pamela Cooper-White, L. William Countryman, Sérgio Coutinho, Pamela Couture, Shannon Craigo-Snell, James L. Crenshaw, David Crowner, Humberto Horacio Cucchetti, Lawrence S. Cunningham, Elizabeth Mason Currier, Emmanuel Cutrone, Mary L. Daniel, David D. Daniels, Robert Darden, Rolf Darge, Isaiah Dau, Jeffry C. Davis, Jane Dawson, Valentin Dedji, John W. de Gruchy, Paul DeHart, Wendy J. Deichmann Edwards, Miguel A. De La Torre, George E. Demacopoulos, Thomas de Mayo, Leah DeVun, Beatriz de Vasconcellos Dias, Dennis C. Dickerson, John M. Dillon, Luis Miguel Donatello, Igor Dorfmann-Lazarev, Susanna Drake, Jonathan A. Draper, N. Dreher Martin, Otto Dreydoppel, Angelyn Dries, A. J. Droge, Francis X. D'Sa, Marilyn Dunn, Nicole Wilkinson Duran, Rifaat Ebied, Mark J. Edwards, William H. Edwards, Leonard H. Ehrlich, Nancy L. Eiesland, Martin Elbel, J. Harold Ellens, Stephen Ellingson, Marvin M. Ellison, Robert Ellsberg, Jean Bethke Elshtain, Eldon Jay Epp, Peter C. Erb, Tassilo Erhardt, Maria Erling, Noel Leo Erskine, Gillian R. Evans, Virginia Fabella, Michael A. Fahey, Edward Farley, Margaret A. Farley, Wendy Farley, Robert Fastiggi, Seena Fazel, Duncan S. Ferguson, Helwar Figueroa, Paul Corby Finney, Kyriaki Karidoyanes FitzGerald, Thomas E. FitzGerald, John R. Fitzmier, Marie Therese Flanagan, Sabina Flanagan, Claude Flipo, Ronald B. Flowers, Carole Fontaine, David Ford, Mary Ford, Stephanie A. Ford, Jim Forest, William Franke, Robert M. Franklin, Ruth Franzén, Edward H. Friedman, Samuel Frouisou, Lorelei F. Fuchs, Jojo M. Fung, Inger Furseth, Richard R. Gaillardetz, Brandon Gallaher, China Galland, Mark Galli, Ismael García, Tharscisse Gatwa, Jean-Marie Gaudeul, Luis María Gavilanes del Castillo, Pavel L. Gavrilyuk, Volney P. Gay, Metropolitan Athanasios Geevargis, Kondothra M. George, Mary Gerhart, Simon Gikandi, Maurice Gilbert, Michael J. Gillgannon, Verónica Giménez Beliveau, Terryl Givens, Beth Glazier-McDonald, Philip Gleason, Menghun Goh, Brian Golding, Bishop Hilario M. Gomez, Michelle A. Gonzalez, Donald K. Gorrell, Roy Gottfried, Tamara Grdzelidze, Joel B. Green, Niels Henrik Gregersen, Cristina Grenholm, Herbert Griffiths, Eric W. Gritsch, Erich S. Gruen, Christoffer H. Grundmann, Paul H. Gundani, Jon P. Gunnemann, Petre Guran, Vidar L. Haanes, Jeremiah M. Hackett, Getatchew Haile, Douglas John Hall, Nicholas Hammond, Daphne Hampson, Jehu J. Hanciles, Barry Hankins, Jennifer Haraguchi, Stanley S. Harakas, Anthony John Harding, Conrad L. Harkins, J. William Harmless, Marjory Harper, Amir Harrak, Joel F. Harrington, Mark W. Harris, Susan Ashbrook Harvey, Van A. Harvey, R. Chris Hassel, Jione Havea, Daniel Hawk, Diana L. Hayes, Leslie Hayes, Priscilla Hayner, S. Mark Heim, Simo Heininen, Richard P. Heitzenrater, Eila Helander, David Hempton, Scott H. Hendrix, Jan-Olav Henriksen, Gina Hens-Piazza, Carter Heyward, Nicholas J. Higham, David Hilliard, Norman A. Hjelm, Peter C. Hodgson, Arthur Holder, M. Jan Holton, Dwight N. Hopkins, Ronnie Po-chia Hsia, Po-Ho Huang, James Hudnut-Beumler, Jennifer S. Hughes, Leonard M. Hummel, Mary E. Hunt, Laennec Hurbon, Mark Hutchinson, Susan E. Hylen, Mary Beth Ingham, H. Larry Ingle, Dale T. Irvin, Jon Isaak, Paul John Isaak, Ada María Isasi-Díaz, Hans Raun Iversen, Margaret C. Jacob, Arthur James, Maria Jansdotter-Samuelsson, David Jasper, Werner G. Jeanrond, Renée Jeffery, David Lyle Jeffrey, Theodore W. Jennings, David H. Jensen, Robin Margaret Jensen, David Jobling, Dale A. Johnson, Elizabeth A. Johnson, Maxwell E. Johnson, Sarah Johnson, Mark D. Johnston, F. Stanley Jones, James William Jones, John R. Jones, Alissa Jones Nelson, Inge Jonsson, Jan Joosten, Elizabeth Judd, Mulambya Peggy Kabonde, Robert Kaggwa, Sylvester Kahakwa, Isaac Kalimi, Ogbu U. Kalu, Eunice Kamaara, Wayne C. Kannaday, Musimbi Kanyoro, Veli-Matti Kärkkäinen, Frank Kaufmann, Léon Nguapitshi Kayongo, Richard Kearney, Alice A. Keefe, Ralph Keen, Catherine Keller, Anthony J. Kelly, Karen Kennelly, Kathi Lynn Kern, Fergus Kerr, Edward Kessler, George Kilcourse, Heup Young Kim, Kim Sung-Hae, Kim Yong-Bock, Kim Yung Suk, Richard King, Thomas M. King, Robert M. Kingdon, Ross Kinsler, Hans G. Kippenberg, Cheryl A. Kirk-Duggan, Clifton Kirkpatrick, Leonid Kishkovsky, Nadieszda Kizenko, Jeffrey Klaiber, Hans-Josef Klauck, Sidney Knight, Samuel Kobia, Robert Kolb, Karla Ann Koll, Heikki Kotila, Donald Kraybill, Philip D. W. Krey, Yves Krumenacker, Jeffrey Kah-Jin Kuan, Simanga R. Kumalo, Peter Kuzmic, Simon Shui-Man Kwan, Kwok Pui-lan, André LaCocque, Stephen E. Lahey, John Tsz Pang Lai, Emiel Lamberts, Armando Lampe, Craig Lampe, Beverly J. Lanzetta, Eve LaPlante, Lizette Larson-Miller, Ariel Bybee Laughton, Leonard Lawlor, Bentley Layton, Robin A. Leaver, Karen Lebacqz, Archie Chi Chung Lee, Marilyn J. Legge, Hervé LeGrand, D. L. LeMahieu, Raymond Lemieux, Bill J. Leonard, Ellen M. Leonard, Outi Leppä, Jean Lesaulnier, Nantawan Boonprasat Lewis, Henrietta Leyser, Alexei Lidov, Bernard Lightman, Paul Chang-Ha Lim, Carter Lindberg, Mark R. Lindsay, James R. Linville, James C. Livingston, Ann Loades, David Loades, Jean-Claude Loba-Mkole, Lo Lung Kwong, Wati Longchar, Eleazar López, David W. Lotz, Andrew Louth, Robin W. Lovin, William Luis, Frank D. Macchia, Diarmaid N. J. MacCulloch, Kirk R. MacGregor, Marjory A. MacLean, Donald MacLeod, Tomas S. Maddela, Inge Mager, Laurenti Magesa, David G. Maillu, Fortunato Mallimaci, Philip Mamalakis, Kä Mana, Ukachukwu Chris Manus, Herbert Robinson Marbury, Reuel Norman Marigza, Jacqueline Mariña, Antti Marjanen, Luiz C. L. Marques, Madipoane Masenya (ngwan'a Mphahlele), Caleb J. D. Maskell, Steve Mason, Thomas Massaro, Fernando Matamoros Ponce, András Máté-Tóth, Odair Pedroso Mateus, Dinis Matsolo, Fumitaka Matsuoka, John D'Arcy May, Yelena Mazour-Matusevich, Theodore Mbazumutima, John S. McClure, Christian McConnell, Lee Martin McDonald, Gary B. McGee, Thomas McGowan, Alister E. McGrath, Richard J. McGregor, John A. McGuckin, Maud Burnett McInerney, Elsie Anne McKee, Mary B. McKinley, James F. McMillan, Ernan McMullin, Kathleen E. McVey, M. Douglas Meeks, Monica Jyotsna Melanchthon, Ilie Melniciuc-Puica, Everett Mendoza, Raymond A. Mentzer, William W. Menzies, Ina Merdjanova, Franziska Metzger, Constant J. Mews, Marvin Meyer, Carol Meyers, Vasile Mihoc, Gunner Bjerg Mikkelsen, Maria Inêz de Castro Millen, Clyde Lee Miller, Bonnie J. Miller-McLemore, Alexander Mirkovic, Paul Misner, Nozomu Miyahira, R. W. L. Moberly, Gerald Moede, Aloo Osotsi Mojola, Sunanda Mongia, Rebeca Montemayor, James Moore, Roger E. Moore, Craig E. Morrison O.Carm, Jeffry H. Morrison, Keith Morrison, Wilson J. Moses, Tefetso Henry Mothibe, Mokgethi Motlhabi, Fulata Moyo, Henry Mugabe, Jesse Ndwiga Kanyua Mugambi, Peggy Mulambya-Kabonde, Robert Bruce Mullin, Pamela Mullins Reaves, Saskia Murk Jansen, Heleen L. Murre-Van den Berg, Augustine Musopole, Isaac M. T. Mwase, Philomena Mwaura, Cecilia Nahnfeldt, Anne Nasimiyu Wasike, Carmiña Navia Velasco, Thulani Ndlazi, Alexander Negrov, James B. Nelson, David G. Newcombe, Carol Newsom, Helen J. Nicholson, George W. E. Nickelsburg, Tatyana Nikolskaya, Damayanthi M. A. Niles, Bertil Nilsson, Nyambura Njoroge, Fidelis Nkomazana, Mary Beth Norton, Christian Nottmeier, Sonene Nyawo, Anthère Nzabatsinda, Edward T. Oakes, Gerald O'Collins, Daniel O'Connell, David W. Odell-Scott, Mercy Amba Oduyoye, Kathleen O'Grady, Oyeronke Olajubu, Thomas O'Loughlin, Dennis T. Olson, J. Steven O'Malley, Cephas N. Omenyo, Muriel Orevillo-Montenegro, César Augusto Ornellas Ramos, Agbonkhianmeghe E. Orobator, Kenan B. Osborne, Carolyn Osiek, Javier Otaola Montagne, Douglas F. Ottati, Anna May Say Pa, Irina Paert, Jerry G. Pankhurst, Aristotle Papanikolaou, Samuele F. Pardini, Stefano Parenti, Peter Paris, Sung Bae Park, Cristián G. Parker, Raquel Pastor, Joseph Pathrapankal, Daniel Patte, W. Brown Patterson, Clive Pearson, Keith F. Pecklers, Nancy Cardoso Pereira, David Horace Perkins, Pheme Perkins, Edward N. Peters, Rebecca Todd Peters, Bishop Yeznik Petrossian, Raymond Pfister, Peter C. Phan, Isabel Apawo Phiri, William S. F. Pickering, Derrick G. Pitard, William Elvis Plata, Zlatko Plese, John Plummer, James Newton Poling, Ronald Popivchak, Andrew Porter, Ute Possekel, James M. Powell, Enos Das Pradhan, Devadasan Premnath, Jaime Adrían Prieto Valladares, Anne Primavesi, Randall Prior, María Alicia Puente Lutteroth, Eduardo Guzmão Quadros, Albert Rabil, Laurent William Ramambason, Apolonio M. Ranche, Vololona Randriamanantena Andriamitandrina, Lawrence R. Rast, Paul L. Redditt, Adele Reinhartz, Rolf Rendtorff, Pål Repstad, James N. Rhodes, John K. Riches, Joerg Rieger, Sharon H. Ringe, Sandra Rios, Tyler Roberts, David M. Robinson, James M. Robinson, Joanne Maguire Robinson, Richard A. H. Robinson, Roy R. Robson, Jack B. Rogers, Maria Roginska, Sidney Rooy, Rev. Garnett Roper, Maria José Fontelas Rosado-Nunes, Andrew C. Ross, Stefan Rossbach, François Rossier, John D. Roth, John K. Roth, Phillip Rothwell, Richard E. Rubenstein, Rosemary Radford Ruether, Markku Ruotsila, John E. Rybolt, Risto Saarinen, John Saillant, Juan Sanchez, Wagner Lopes Sanchez, Hugo N. Santos, Gerhard Sauter, Gloria L. Schaab, Sandra M. Schneiders, Quentin J. Schultze, Fernando F. Segovia, Turid Karlsen Seim, Carsten Selch Jensen, Alan P. F. Sell, Frank C. Senn, Kent Davis Sensenig, Damían Setton, Bal Krishna Sharma, Carolyn J. Sharp, Thomas Sheehan, N. Gerald Shenk, Christian Sheppard, Charles Sherlock, Tabona Shoko, Walter B. Shurden, Marguerite Shuster, B. Mark Sietsema, Batara Sihombing, Neil Silberman, Clodomiro Siller, Samuel Silva-Gotay, Heikki Silvet, John K. Simmons, Hagith Sivan, James C. Skedros, Abraham Smith, Ashley A. Smith, Ted A. Smith, Daud Soesilo, Pia Søltoft, Choan-Seng (C. S.) Song, Kathryn Spink, Bryan Spinks, Eric O. Springsted, Nicolas Standaert, Brian Stanley, Glen H. Stassen, Karel Steenbrink, Stephen J. Stein, Andrea Sterk, Gregory E. Sterling, Columba Stewart, Jacques Stewart, Robert B. Stewart, Cynthia Stokes Brown, Ken Stone, Anne Stott, Elizabeth Stuart, Monya Stubbs, Marjorie Hewitt Suchocki, David Kwang-sun Suh, Scott W. Sunquist, Keith Suter, Douglas Sweeney, Charles H. Talbert, Shawqi N. Talia, Elsa Tamez, Joseph B. Tamney, Jonathan Y. Tan, Yak-Hwee Tan, Kathryn Tanner, Feiya Tao, Elizabeth S. Tapia, Aquiline Tarimo, Claire Taylor, Mark Lewis Taylor, Bishop Abba Samuel Wolde Tekestebirhan, Eugene TeSelle, M. Thomas Thangaraj, David R. Thomas, Andrew Thornley, Scott Thumma, Marcelo Timotheo da Costa, George E. “Tink” Tinker, Ola Tjørhom, Karen Jo Torjesen, Iain R. Torrance, Fernando Torres-Londoño, Archbishop Demetrios [Trakatellis], Marit Trelstad, Christine Trevett, Phyllis Trible, Johannes Tromp, Paul Turner, Robert G. Tuttle, Archbishop Desmond Tutu, Peter Tyler, Anders Tyrberg, Justin Ukpong, Javier Ulloa, Camillus Umoh, Kristi Upson-Saia, Martina Urban, Monica Uribe, Elochukwu Eugene Uzukwu, Richard Vaggione, Gabriel Vahanian, Paul Valliere, T. J. Van Bavel, Steven Vanderputten, Peter Van der Veer, Huub Van de Sandt, Louis Van Tongeren, Luke A. Veronis, Noel Villalba, Ramón Vinke, Tim Vivian, David Voas, Elena Volkova, Katharina von Kellenbach, Elina Vuola, Timothy Wadkins, Elaine M. Wainwright, Randi Jones Walker, Dewey D. Wallace, Jerry Walls, Michael J. Walsh, Philip Walters, Janet Walton, Jonathan L. Walton, Wang Xiaochao, Patricia A. Ward, David Harrington Watt, Herold D. Weiss, Laurence L. Welborn, Sharon D. Welch, Timothy Wengert, Traci C. West, Merold Westphal, David Wetherell, Barbara Wheeler, Carolinne White, Jean-Paul Wiest, Frans Wijsen, Terry L. Wilder, Felix Wilfred, Rebecca Wilkin, Daniel H. Williams, D. Newell Williams, Michael A. Williams, Vincent L. Wimbush, Gabriele Winkler, Anders Winroth, Lauri Emílio Wirth, James A. Wiseman, Ebba Witt-Brattström, Teofil Wojciechowski, John Wolffe, Kenman L. Wong, Wong Wai Ching, Linda Woodhead, Wendy M. Wright, Rose Wu, Keith E. Yandell, Gale A. Yee, Viktor Yelensky, Yeo Khiok-Khng, Gustav K. K. Yeung, Angela Yiu, Amos Yong, Yong Ting Jin, You Bin, Youhanna Nessim Youssef, Eliana Yunes, Robert Michael Zaller, Valarie H. Ziegler, Barbara Brown Zikmund, Joyce Ann Zimmerman, Aurora Zlotnik, Zhuo Xinping
- Edited by Daniel Patte, Vanderbilt University, Tennessee
-
- Book:
- The Cambridge Dictionary of Christianity
- Published online:
- 05 August 2012
- Print publication:
- 20 September 2010, pp xi-xliv
-
- Chapter
- Export citation
Aluminum Nitride Micro-Channels Grown via Metal Organic Vapor Phase Epitaxy for MEMs Applications
- L. E. Rodak, Sridhar Kuchibhatla, P. Famouri, Ting Liu, D. Korakakis
-
- Journal:
- MRS Online Proceedings Library Archive / Volume 1040 / 2007
- Published online by Cambridge University Press:
- 01 February 2011, 1040-Q09-28
- Print publication:
- 2007
-
- Article
- Export citation
-
Aluminum nitride (AlN) is a promising material for a number of applications due to its temperature and chemical stability. Furthermore, AlN maintains its piezoelectric properties at higher temperatures than more commonly used materials, such as Lead Zirconate Titanate (PZT) [1, 2], making AlN attractive for high temperature micro and nano-electromechanical (MEMs and NEMs) applications including, but not limited to, high temperature sensors and actuators, micro- channels for fuel cell applications, and micromechanical resonators.
This work presents a novel AlN micro-channel fabrication technique using Metal Organic Vapor Phase Epitaxy (MOVPE). AlN easily nucleates on dielectric surfaces due to the large sticking coefficient and short diffusion length of the aluminum species resulting in a high quality polycrystalline growth on typical mask materials, such as silicon dioxide and silicon nitride [3,4]. The fabrication process introduced involves partially masking a substrate with a silicon dioxide striped pattern and then growing AlN via MOVPE simultaneously on the dielectric mask and exposed substrate. A buffered oxide etch is then used to remove the underlying silicon dioxide and leave a free standing AlN micro-channel. The width of the channel has been varied from 5 ìm to 110 ìm and the height of the air gap from 130 nm to 800 nm indicating the stability of the structure. Furthermore, this versatile process has been performed on (111) silicon, c-plane sapphire, and gallium nitride epilayers on sapphire substrates. Reflection High Energy Electron Diffraction (RHEED), Atomic Force Microscopy (AFM), and Raman measurements have been taken on channels grown on each substrate and indicate that the substrate is influencing the growth of the AlN micro-channels on the SiO2 sacrificial layer.
The buckling and stretching of a viscida
- J. D. Buckmaster, A. Nachman, L. Ting
-
- Journal:
- Journal of Fluid Mechanics / Volume 69 / Issue 1 / 13 May 1975
- Published online by Cambridge University Press:
- 29 March 2006, pp. 1-20
-
- Article
- Export citation
-
We consider the deformation of a thin thread of viscous liquid (viscida) as its ends are slowly moved together. Equations are deduced which are capable of describing the motion of the thread when the displacement of the axis from a straight line is either on the scale of the thread thickness (problem 1) or on the much larger scale of the thread length (problem 2). In the former case it is shown analytically that an arbitrary initial displacement evolves in such a way that, as the appropriately scaled time τ becomes large, the first mode of the disturbance emerges in a dominant role with an amplitude that is proportional to τ½ and independent of the initial amplitude. This provides the initial condition for problem 2, for which a numerical description is obtained.
In addition, we analyse the situation when the ends of the viscida are slowly pulled apart. In this case the high frequency end of the spectrum dominates as an arbitrary disturbance decays.
Changes in Optical Properties of GaAsN During Annealing
- Ting Liu, Sandeep Chandril, Eric D. Schires, Nianqiang Wu, Xinqi Chen, Dimitris Korakakis, Thomas H. Myers
-
- Journal:
- MRS Online Proceedings Library Archive / Volume 891 / 2005
- Published online by Cambridge University Press:
- 01 February 2011, 0891-EE11-05
- Print publication:
- 2005
-
- Article
- Export citation
-
GaAs1−xNx layers and quantum dot-like structures were grown on (100) GaAs substrates by molecular beam epitaxy. The dependence of photoluminescence emission spectra on annealing temperature is consistent with literature at lower temperatures but after annealing at 750 °C a net red-shift is consistently observed. X-ray photoelectron spectroscopy measurements indicate that for different annealing times and temperatures, the nitrogen and arsenic surface concentrations changed compared to that of as-grown samples, specifically arsenic is lost from the material. Raman measurements are consistent with the trends in photoluminescence and also suggest the loss of arsenic occurs at higher annealing temperatures in both samples capped with GaAs and uncapped samples.