103 research outputs found
Flipping quantum coins
Coin flipping is a cryptographic primitive in which two distrustful parties
wish to generate a random bit in order to choose between two alternatives. This
task is impossible to realize when it relies solely on the asynchronous
exchange of classical bits: one dishonest player has complete control over the
final outcome. It is only when coin flipping is supplemented with quantum
communication that this problem can be alleviated, although partial bias
remains. Unfortunately, practical systems are subject to loss of quantum data,
which restores complete or nearly complete bias in previous protocols. We
report herein on the first implementation of a quantum coin-flipping protocol
that is impervious to loss. Moreover, in the presence of unavoidable
experimental noise, we propose to use this protocol sequentially to implement
many coin flips, which guarantees that a cheater unwillingly reveals
asymptotically, through an increased error rate, how many outcomes have been
fixed. Hence, we demonstrate for the first time the possibility of flipping
coins in a realistic setting. Flipping quantum coins thereby joins quantum key
distribution as one of the few currently practical applications of quantum
communication. We anticipate our findings to be useful for various
cryptographic protocols and other applications, such as an online casino, in
which a possibly unlimited number of coin flips has to be performed and where
each player is free to decide at any time whether to continue playing or not.Comment: 17 pages, 3 figure
MoSi Superconducting Nanowire Single-Photon Detectors on GaAs for On-Chip Integration
We report on MoSi-based superconducting nanowire single-photon detectors on a
gallium arsenide substrate. MoSi deposited on a passivated GaAs surface has the
same critical temperature as MoSi deposited on silicon. The critical
temperature decreases slightly on depositing MoSi directly on the native oxide
of GaAs. Hence, MoSi works well as a thin-film superconductor on GaAs. We
propose that the amorphous structure of MoSi ensures compatibility with the
GaAs matrix. Superconducting nanowire single-photon detectors (SNSPDs) are
fabricated with MoSi on GaAs using a meander-wire design. The SNSPD metrics are
very similar to those of devices fabricated with the same procedure on a
silicon substrate. We observe a plateau in the response-versus-bias curve
signalling a saturated internal quantum efficiency. The plateau remains even at
an elevated temperature, 2.2 K, at a wavelength of 980 nm. We achieve a timing
jitter of 50 ps and a recovery time of 29 ns. These results point to the
promise of integrating MoSi SNSPDs with GaAs photonic circuits
Closed-system drug-transfer devices plus safe handling of hazardous drugs versus safe handling alone for reducing exposure to infusional hazardous drugs in healthcare staff
BACKGROUND: Occupational exposure to hazardous drugs can decrease fertility and result in miscarriages, stillbirths, and cancers in healthcare staff. Several recommended practices aim to reduce this exposure, including protective clothing, gloves, and biological safety cabinets ('safe handling'). There is significant uncertainty as to whether using closed-system drug-transfer devices (CSTD) in addition to safe handling decreases the contamination and risk of staff exposure to infusional hazardous drugs compared to safe handling alone. OBJECTIVES: To assess the effects of closed-system drug-transfer of infusional hazardous drugs plus safe handling versus safe handling alone for reducing staff exposure to infusional hazardous drugs and risk of staff contamination. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, OSH-UPDATE, CINAHL, Science Citation Index Expanded, economic evaluation databases, the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov to October 2017. SELECTION CRITERIA: We included comparative studies of any study design (irrespective of language, blinding, or publication status) that compared CSTD plus safe handling versus safe handling alone for infusional hazardous drugs. DATA COLLECTION AND ANALYSIS: Two review authors independently identified trials and extracted data. We calculated the risk ratio (RR) and mean difference (MD) with 95% confidence intervals (CI) using both fixed-effect and random-effects models. We assessed risk of bias according to the risk of bias in non-randomised studies of interventions (ROBINS-I) tool, used an intracluster correlation coefficient of 0.10, and we assessed the quality of the evidence using GRADE. MAIN RESULTS: We included 23 observational cluster studies (358 hospitals) in this review. We did not find any randomised controlled trials or formal economic evaluations. In 21 studies, the people who used the intervention (CSTD plus safe handling) and control (safe handling alone) were pharmacists or pharmacy technicians; in the other two studies, the people who used the intervention and control were nurses, pharmacists, or pharmacy technicians. The CSTD used in the studies were PhaSeal (13 studies), Tevadaptor (1 study), SpikeSwan (1 study), PhaSeal and Tevadaptor (1 study), varied (5 studies), and not stated (2 studies). The studies' descriptions of the control groups were varied. Twenty-one studies provide data on one or more outcomes for this systematic review. All the studies are at serious risk of bias. The quality of evidence is very low for all the outcomes.There is no evidence of differences in the proportion of people with positive urine tests for exposure between the CSTD and control groups for cyclophosphamide alone (RR 0.83, 95% CI 0.46 to 1.52; I² = 12%; 2 studies; 2 hospitals; 20 participants; CSTD: 76.1% versus control: 91.7%); cyclophosphamide or ifosfamide (RR 0.09, 95% CI 0.00 to 2.79; 1 study; 1 hospital; 14 participants; CSTD: 6.4% versus control: 71.4%); and cyclophosphamide, ifosfamide, or gemcitabine (RR not estimable; 1 study; 1 hospital; 36 participants; 0% in both groups).There is no evidence of a difference in the proportion of surface samples contaminated in the pharmacy areas or patient-care areas for any of the drugs except 5-fluorouracil, which was lower in the CSTD group than in the control (RR 0.65, 95% CI 0.43 to 0.97; 3 studies, 106 hospitals, 1008 samples; CSTD: 9% versus control: 13.9%).The amount of cyclophosphamide was lower in pharmacy areas in the CSTD group than in the control group (MD -49.34 pg/cm², 95% CI -84.11 to -14.56, I² = 0%, 7 studies; 282 hospitals, 1793 surface samples). Additionally, one interrupted time-series study (3 hospitals; 342 samples) demonstrated a change in the slope between pre-CSTD and CSTD (3.9439 pg/cm², 95% CI 1.2303 to 6.6576; P = 0.010), but not between CSTD and post-CSTD withdrawal (-1.9331 pg/cm², 95% CI -5.1260 to 1.2598; P = 0.20). There is no evidence of difference in the amount of the other drugs between CSTD and control groups in the pharmacy areas or patient-care areas.None of the studies report on atmospheric contamination, blood tests, or other measures of exposure to infusional hazardous drugs such as urine mutagenicity, chromosomal aberrations, sister chromatid exchanges, or micronuclei induction.None of the studies report short-term health benefits such as reduction in skin rashes, medium-term reproductive health benefits such as fertility and parity, or long-term health benefits related to the development of any type of cancer or adverse events.Five studies (six hospitals) report the potential cost savings through the use of CSTD. The studies used different methods of calculating the costs, and the results were not reported in a format that could be pooled via meta-analysis. There is significant variability between the studies in terms of whether CSTD resulted in cost savings (the point estimates of the average potential cost savings ranged from (2017) USD -642,656 to (2017) USD 221,818). AUTHORS' CONCLUSIONS: There is currently no evidence to support or refute the routine use of closed-system drug transfer devices in addition to safe handling of infusional hazardous drugs, as there is no evidence of differences in exposure or financial benefits between CSTD plus safe handling versus safe handling alone (very low-quality evidence). None of the studies report health benefits.Well-designed multicentre randomised controlled trials may be feasible depending upon the proportion of people with exposure. The next best study design is interrupted time-series. This design is likely to provide a better estimate than uncontrolled before-after studies or cross-sectional studies. Future studies may involve other alternate ways of reducing exposure in addition to safe handling as one intervention group in a multi-arm parallel design or factorial design trial. Future studies should have designs that decrease the risk of bias and enable measurement of direct health benefits in addition to exposure. Studies using exposure should be tested for a relevant selection of hazardous drugs used in the hospital to provide an estimate of the exposure and health benefits of using CSTD. Steps should be undertaken to ensure that there are no other differences between CSTD and control groups, so that one can obtain a reasonable estimate of the health benefits of using CSTD
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Identifying factors likely to influence compliance with diagnostic imaging guideline recommendations for spine disorders among chiropractors in North America: a focus group study using the Theoretical Domains Framework
Background: The Theoretical Domains Framework (TDF) was developed to investigate determinants of specific clinical behaviors and inform the design of interventions to change professional behavior. This framework was used to explore the beliefs of chiropractors in an American Provider Network and two Canadian provinces about their adherence to evidence-based recommendations for spine radiography for uncomplicated back pain. The primary objective of the study was to identify chiropractors’ beliefs about managing uncomplicated back pain without xrays and to explore barriers and facilitators to implementing evidence-based recommendations on lumbar spine xrays. A secondary objective was to compare chiropractors in the United States and Canada on their beliefs regarding the use of spine x-rays.
Methods: Six focus groups exploring beliefs about managing back pain without x-rays were conducted with a purposive sample. The interview guide was based upon the TDF. Focus groups were digitally recorded, transcribed verbatim, and analyzed by two independent assessors using thematic content analysis based on the TDF.
Results: Five domains were identified as likely relevant. Key beliefs within these domains included the following: conflicting comments about the potential consequences of not ordering x-rays (risk of missing a pathology, avoiding adverse treatment effects, risks of litigation, determining the treatment plan, and using x-ray-driven techniques contrasted with perceived benefits of minimizing patient radiation exposure and reducing costs; beliefs about consequences); beliefs regarding professional autonomy, professional credibility, lack of standardization, and agreement with guidelines widely varied (social/professional role & identity); the influence of formal training, colleagues, and patients also appeared to be important factors (social influences); conflicting comments regarding levels of confidence and comfort in managing patients without x-rays (belief about capabilities); and guideline awareness and agreements (knowledge).
Conclusions: Chiropractors’ use of diagnostic imaging appears to be influenced by a number of factors. Five key domains may be important considering the presence of conflicting beliefs, evidence of strong beliefs likely to impact the behavior of interest, and high frequency of beliefs. The results will inform the development of a theorybased survey to help identify potential targets for behavioral-change strategies
Evidence-based practice, research utilization, and knowledge translation in chiropractic: a scoping review
Background: Evidence-based practice (EBP) gaps are widespread across health disciplines. Understanding factors supporting the uptake of evidence can inform the design of strategies to narrow these EBP gaps. Although research utilization (RU) and the factors associated with EBP have been reported in several health disciplines, to date this area has not been reviewed comprehensively in the chiropractic profession. The purpose of this review was to report on the current state of knowledge on EBP, RU, and knowledge translation (KT) in chiropractic. Methods: A scoping review using the Arksey and O'Malley framework was used to systematically select and summarize existing literature. Searches were conducted using a combination of keywords and MeSH terms from the earliest date available in each database to May 2015. Quantitative and thematic analyses of the selected literature were conducted. Results: Nearly 85 % (56/67) of the included studies were conducted in Canada, USA, UK or Australia. Thematic analysis for the three categories (EBP, RU, KT) revealed two themes related to EBP (attitudes and beliefs of chiropractors; implementation of EBP), three related to RU (guideline adherence; frequency and sources of information accessed; and perceived value of websites and search engines), and three related to KT (knowledge practice gaps; barriers and facilitators to knowledge use; and selection, tailoring, and implementation of interventions). EBP gaps were noted in the areas of assessment of activity limitation, determination of psychosocial factors influencing pain, general health indicators, establishing a prognosis, and exercise prescription. While most practitioners believed EBP and research to be important and a few studies suggested that traditional and online educational strategies could improve patient care, use of EBP and guideline adherence varied widely. Conclusion: Findings suggest that the majority of chiropractors hold favourable attitudes and beliefs toward EBP. However, much remains to be done for chiropractors to routinely apply evidence into clinical practice. Educational strategies aimed at practicing chiropractors can lead to more EBP and improved patient care. The chiropractic profession requires more robust dissemination and implementation research to improve guideline adherence and patient health outcomes
Historical influence on the practice of chiropractic radiology: part II - thematic analysis on the opinions of diplomates of the American Chiropractic College of Radiology about the future
Background: Over the past 20 years, various authors have addressed the question of the future of chiropractic. Most were positive about the future, with some advocating evidence-based practice and integration with mainstream healthcare, some advocating continued separation with an emphasis on subluxation-based care or the traditional/historical paradigm of chiropractic, and some calling for tolerance and unity. No papers were found specifically inquiring about the future of chiropractic radiology.
Methods: The study population consisted of all current members of the American Chiropractic College of Radiology (ACCR), estimated at 190 people, known as chiropractic radiologists or Diplomates of the American Chiropractic Board of Radiology (DACBRs). An internet-based, anonymous survey using SurveyMonkey was implemented, supplemented by hard copies distributed at a conference. The main point of interest for this paper is the final item of the overall questionnaire. This item inquired about the future of chiropractic radiology. Thematic analysis was used on the responses, coded in both constructionist and inductive ways to extract both a general outlook and more specific themes. The inductive themes were also assigned secondarily to a SWOT (strengths, weaknesses, opportunities, and threats) analysis.
Results: The overall response rate to the survey was 38% (73/190); within the group of respondents, 71 of 73 (98%) answered the item that is the subject of this paper. Opinions on the outlook for chiropractic radiology in the future were more negative than positive, with 14 respondents giving a positive outlook, 26 negative, and 14 non-committal. 28 respondents advocated integration with the wider healthcare community, 11 recommended emphasising separateness or a focus on working within chiropractic, and 15 did not express an opinion on this issue. Ten strengths were noted, 11 weaknesses, 57 opportunities, and 30 threats.
Conclusions: The increasing necessity of demonstrating evidence for diagnostic and therapeutic procedures in healthcare makes it likely that chiropractic radiologists and the wider chiropractic profession will need to take a more active position on evidence-based practice. Re-evaluation of guidelines and legislation as well as enforcement policies and practices will be necessary. The consequences of failing to do so may include increased marginalisation and reduced viability as a profession
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Doctors of chiropractic working with or within integrated healthcare delivery systems: a scoping review protocol
Introduction Back and neck pain are the leading causes of disability worldwide. Doctors of chiropractic (DCs) are trained to manage these common conditions and can provide non-pharmacological treatment aligned with international clinical practice guidelines. Although DCs practice in over 90 countries, chiropractic care is rarely available within integrated healthcare delivery systems. A lack of DCs in private practice, particularly in low-income communities, may also limit access to chiropractic care. Improving collaboration between medical providers and community-based DCs, or embedding DCs in medical settings such as hospitals or community health centres, will improve access to evidence-based care for musculoskeletal conditions. Methods and analyses This scoping review will map studies of DCs working with or within integrated healthcare delivery systems. We will use the recommended six-step approach for scoping reviews. We will search three electronic data bases including Medline, Embase and Web of Science. Two investigators will independently review all titles and abstracts to identify relevant records, screen the full-text articles of potentially admissible records, and systematically extract data from selected articles. We will include studies published in English from 1998 to 2020 describing medical settings that have established formal relationships with community-based DCs (eg, shared medical record) or where DCs practice in medical settings. Data extraction and reporting will be guided by the Proctor Conceptual Model for Implementation Research, which has three domains: clinical intervention, implementation strategies and outcome measurement. Stakeholders from diverse clinical fields will offer feedback on the implications of our findings via a web-based survey. Ethics and dissemination Ethics approval will not be obtained for this review of published and publicly accessible data, but will be obtained for the web-based survey. Our results will be disseminated through conference presentations and a peer-reviewed publication. Our findings will inform implementation strategies that support the adoption of chiropractic care within integrated healthcare delivery systems.
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