Project description:SIGNIFICANCE:Uncorrected refractive error is a prevalent problem throughout the world especially among the low-income population who have limited access to professional eye care and cannot afford eyeglasses. PURPOSE:The purpose of this study was to evaluate the accuracy and usability of a low-cost, portable, smartphone-based autorefractor (Netra, EyeNetra Inc., Somerville, MA) in adults. METHODS:A cross-sectional study was conducted to compare the portable refractor with subjective (manifest and cycloplegic) refraction for sequential adult participants with best-corrected visual acuity of 20/40 or greater. For each method of refraction, the spherical equivalent was calculated. Differences between methods were tested with linear mixed regression models. A validated usability questionnaire was administered regarding ease of use (100-point scale, higher scores better) for the portable autorefractor. RESULTS:Eighty-seven subjects (152 eyes) were studied (age range, 20 to 90 years; mean ± standard deviation, 51.9 ± 18.3 years). Mean spherical equivalent by the portable device was -2.76 D (range, -14.75 to 3.63 D) compared with -2.49 D (range, -15.25 to 4.25 D) by manifest refraction. The mean relative difference in spherical equivalent between methods was -0.27 D (P = .001, significantly different than 0 D). The mean absolute difference between methods was 0.69 D (P < .001, significantly different than 0.5-D absolute difference). Similar results were found when comparing spherical equivalent between Netra and cycloplegic refraction methods. Subjects reported average ease of use for the Netra of 75.4 ± 19.8. CONCLUSIONS:The portable autorefractor had small but clinically significant differences from subjective refraction. The device's scores on the usability scale indicate good overall patient acceptance. The device may be valuable for use where there is limited access to a trained refractionist.
Project description:PurposeSymptomatic adult spinal deformity (ASD) with an extremely variable presentation with pain, with and without neurogenic leg pain, and/or disturbed sagittal and coronal balance, causes a significant societal burden of disease. It is an important consequence of the aging adult population, generating a plethora of spine-related interventions with variable treatment efficacy and consistently high costs. Recent years have witnessed more than a threefold increase in the prevalence and treatment of ASD, and further increases over the coming decades are expected with the growing elderly population worldwide. The ability to monitor and assess clinical outcomes has not kept pace with these developments. This paper addresses the pressing need to provide a set of common outcome metrics for this growing group of patients with back pain and other disabilities due to an adult spinal deformity.MethodsThe standard outcome set was created by a panel with global representation, using a thorough modified Delphi procedure. The three-tiered outcome hierarchy (Porter) was used as a framework to capture full cycle of care. The standardized language of the International Classification of Functioning, Disability and Health (WHO-ICF) was used.ResultsConsensus was reached on a core set of 25 WHO-ICF outcome domains ('What to measure'); on the accompanying globally available clinician and patient reported measurement instruments and definitions ('How to measure'), and on the timing of the measurements ('When to measure'). The current work has brought to light domains not routinely reported in the spinal literature (such as pulmonary function, return to work, social participation), and domains for which no adequate instruments have yet been identified (such as how to clinically quantify in routine practice lumbar spinal stenosis, neurogenic claudication, radicular pain, and loss of lower extremity motor function).ConclusionA standard outcome set was developed for patients undergoing treatment for adult spinal deformity using globally available outcome metrics. The current framework can be considered a reference for further work, and may provide a starting point for routine methodical and systematic monitoring of outcomes. Post-COVID e-health may accelerate the routine capture of these types of data.
Project description:The lack of reproducibility in many areas of experimental science has a number of causes, including a lack of transparency and precision in the description of experimental approaches. This has far-reaching consequences, including wasted resources and slowing of progress. Additionally, the large number of laboratories around the world publishing articles on a given topic make it difficult, if not impossible, for individual researchers to read all of the relevant literature. Consequently, centralized databases are needed to facilitate the generation of new hypotheses for testing. One strategy to improve transparency in experimental description, and to allow the development of frameworks for computer-readable knowledge repositories, is the adoption of uniform reporting standards, such as common data elements (data elements used in multiple clinical studies) and minimum information standards. This article describes a minimum information standard for spinal cord injury (SCI) experiments, its major elements, and the approaches used to develop it. Transparent reporting standards for experiments using animal models of human SCI aim to reduce inherent bias and increase experimental value.
Project description:This paper presents an ecological performance analysis and optimization for an air-standard irreversible Dual-Atkinson cycle (DAC) based on the ecological coefficient of performance (ECOP) criterion which includes internal irreversibilities, heat leak, and finite-rate of heat transfer. A comprehensive numerical analysis has been realized so as to investigate the global and optimal performances of the cycle. The results obtained based on the ECOP criterion are compared with a different ecological function which is named as the ecologic objective-function and with the maximum power output conditions. The results have been attained introducing the compression ratio, cut-off ratio, pressure ratio, Atkinson cycle ratio, source temperature ratio, and internal irreversibility parameter. The change of cycle performance with respect to these parameters is investigated and graphically presented.
Project description:This research focuses on developing an improved and robust measurement for emergency department (ED) performance and a criterion standard for global use via kinetic analysis. Based on kinetic approach, the input-throughput-output conceptual model of ED crowding is compared to the procedure of enzyme catalysis. All in average, the retented patients in EDs are defined as substrate (S), whereas the patients who depart the EDs as product (P). Therefore, the average ED departure velocity (V) can be presented as (P)divided by a given time (t) of the ED length of stay (LOS). The S-V and S²-P plots are depicted hourly for the kinetic analysis. The long-term stability of the kinetic parameters is ascertained by the method of coefficient of variation (CV). The participants collected for this study are from the EDs of Changhua Christian Medical Center and the five branched hospitals, all located in Taiwan. Based on the S-V plot analysis, the results clearly show 2 curves, an upper and a lower curve. The timeline of the lower curve includes approximately the total ED busy hours, and thus it can be used for the subsequent kinetic analysis. In order to explore the adequate kinetic parameters for ED performance, the try-and-error process was followed in this study. As a result, the S²-V plots adapted from the lower curves show the best linear regression of S² on V with a good coefficient of determination (R). The Pan-Wen constant (PW), which is the slope of the liner regression line, and the ED medical personnel unit turnover number (EDMPU TON) were deduced from the kinetic meanings of (Equation is included in full-text article.)plots. In this research, the 2 kinetic parameters, PW and EDMPU TON were applied for the ED performance evaluations. An innovative relationship between the ED retented patients and the ED departure velocity is verified as PW; whereas, a feasible kinetic parameter, the EDMPU TON explicates the teamwork efficiency of the ED providers. Moreover, the EDMPU TON may not only be a reliable universal criterion standard for the ED performance, but also a valuable reference for both ED providers and payers.
Project description:Discovering a generalized criterion that can predict the mechanical failure of various different structural materials is one of ultimate goals for scientists in both material and mechanics communities. Since the first study on the failure criterion of materials by Galileo, about three centuries have passed. Now we eventually find the "generalized energy criterion", as presented here, which appears to be one universal law for various different kinds of materials. The validity of the energy criterion for quantitatively predicting the failure is experimentally confirmed using a metallic glass. The generalized energy criterion reveals the competition and interaction between shear and cleavage, the two fundamental inherent failure mechanisms, and thus provides new physical insights into the failure prediction of materials and structural components.
Project description:Epidemiological studies utilizing administrative databases use the International Classification of Diseases, Ninth Revision, Clinical Modification code (577.1) to identify patients with chronic pancreatitis (CP). We hypothesized that coding of CP in these databases is inaccurate.We retrospectively reviewed the records of 1343 consecutive patients having an International Classification of Diseases, Ninth Revision, Clinical Modification code 577.1 between October 1, 2005, and November 1, 2008. We labeled patients as definite CP or non-CP, defined as fulfilling any of the 3 diagnostic criteria for definite CP: Mayo, Ammann's, and the Japanese Pancreas Society criteria.Six hundred fifty-eight subjects (49%) had definite CP. Definite CP among Mayo, Ammann's, and Japanese Pancreas Society criteria was similar (49.0, 42.1, and 43.8, respectively); 84.3% of the definite CP fulfilled all 3 criteria, 6.7% fulfilled 2, and 9.0% filled 1 criterion. Etiologies of definite CP were definite/suspected nonalcohol (57.8%) or alcohol (33.5%) and not reported (8.7%). In non-CP (n = 685), 93.7% had available imaging (5.7% had endoscopic ultrasonography ?5 or Cambridge II-III scores), and 63.5% had symptoms suggestive of CP but did not fulfill other features for definite CP. The CP versus non-CP groups had similar mean ages but significantly more men and patients ever smoking and ever drinking alcohol.Fifty-one percent of subjects coded as CP do not fulfill the diagnostic criteria for definite CP. Relying solely on the International Classification of Diseases, Clinical Modification code for CP in administrative databases may lead to erroneous epidemiological conclusions.
Project description:To investigate macular perfusion in healthy Chinese individuals and examine its dependence on age and sex.Healthy adult Chinese individuals were recruited. Macular perfusion was measured by spectral-domain optical coherence tomography (OCT) using the split-spectrum amplitude-decorrelation angiography (SSADA) algorithm. The parafoveal flow index and vessel area density as well as the area of the foveal capillary-free zone (CFZ) were quantified.A total of 76 eyes in 45 subjects were included (20 males and 25 females, mean age 36 ± 11 years). The mean parafoveal flow index was 0.099 ± 0.013; the mean vessel area density was 0.891 ± 0.073; and the mean CFZ area was 0.474 ± 0.172 mm2. All three parameters were significantly correlated with age (flow index: P = 0.00; vessel area density: P = 0.00; CFZ area: P = 0.02). The flow index and vessel area density decreased annually by 0.6% and 0.4%, respectively, and CFZ area increased by 1.48% annually. The CFZ area was larger in females than in males, while all three parameters seemed to change more rapidly with age in males than in females.In healthy Chinese eyes, macular perfusion decreased with increasing age, and decreased more rapidly in males than in females. The application of OCT angiograms may provide a useful approach for monitoring macular perfusion, although caution must be exercised with regard to age- and sex-related variations.