PERFORMANCE CHARACTERISTICS CONSIDERING POROSITY CHANGE DUE TO CROSS SECTIONAL DERFORMATION OF WAVE DISSIPATING WORK AND PROPOSAL OF REPAIR CRITERIA

2021 ◽  
Vol 77 (2) ◽  
pp. I_733-I_738
Author(s):  
Hiroshi MATSUSHITA ◽  
Hiroyuki KAWAMURA ◽  
Takayuki HIRAYAMA ◽  
Kouhei OGUMA ◽  
Tetsuya HIRAISHI ◽  
...  
Keyword(s):  
Performance Characteristics ◽  
Cross Sectional ◽  
Porosity Change

scholarly journals 1134. Novel T2Candida Panel Assay Compared With Blood Cultures for Detection of Candidemia in Transplant and Non-Transplant Patients

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S340-S341
Author(s):  
Noman Hussain ◽  
Zohra Chaudhry ◽  
Hira Rizvi ◽  
Odaliz Abreu-Lanfranco ◽  
Mayur Ramesh ◽  
...  
Keyword(s):  
Turnaround Time ◽  
Performance Characteristics ◽  
Clinical Implications ◽  
Good Sensitivity ◽  
Antifungal Stewardship ◽  
Cross Sectional ◽  
Transplant Patients ◽  
Educational Grant ◽  
Species Specific ◽  
Sensitivity Specificity

Abstract Background Blood culture (BC) the current “gold” standard for detection of candidemia has a sensitivity of ~50% and turnaround time (TAT) of 2–5 days. T2Candida Panel (T2) a magnetic resonance nano-diagnostic test done directly on blood samples detects C. albicans/C. tropicalis, C. krusei/C. glabrata, and C. parapsilosis. Clinical trials of T2 showed good sensitivity, specificity, NPV 99% and TAT of 3–5 hours. The performance of T2 in high-risk transplant (Tx) population is unknown. T2 was implemented at our institution in October 2015. We evaluated the performance characteristics of T2 and BC in our Tx and non-transplant (non-Tx) patient populations. Methods This was an observational, retrospective, cross-sectional evaluation of patients with suspected candidemia that had T2 done from October 2015 to October 2017 at a multihospital healthcare system in Detroit, MI. Performance characteristics of the T2 and BC in Tx and non-Tx patients were compared. BC obtained within 7 days before or after the T2 test were included in the analysis. TAT, sensitivity, specificity, PPV and NPV were calculated using positive BC as the standard. Differences between groups were assessed using two sample proportions testing at α = 0.05. Results A total of 1,272 patients with suspected candidemia had T2 done: 1,162 (91%) non-Tx and 110 (9%) Tx patients. Average TAT for T2 was 13 hours (5–41) vs. 34 hours (21–109) to initial positive BC result and 4 days (3–13) to species-specific BC result. In four non-Tx patients with negative T2, C. lusitaniae, C. dubliniensis, and C. kefyr were isolated in BC. Performance characteristics of T2 and BC in the two groups is shown (Table 1). Of the T2+/BC− cases (n = 102), 9% had retinitis and 9% had invasive candidiasis. Conclusion The rapid TAT, good sensitivity, and high NPV of T2 in Tx patients has clinical implications and can help support antifungal stewardship efforts in this population. The clinical significance of T2 positivity in the presence of negative BC needs further investigation. Disclosures G. Alangaden, T2 Biosystems: Speaker’s Bureau, Educational grant and Speaker honorarium.

scholarly journals Comparing the performance characteristics of CSF-TRUST and CSF-VDRL for syphilis: a cross-sectional study

BMJ Open ◽  
2013 ◽  
Vol 3 (2) ◽  
pp. e002204 ◽  
Author(s):  
Weiming Gu ◽  
Yang Yang ◽  
Lei Wu ◽  
Sheng Yang ◽  
Lai-King Ng
Keyword(s):  
Cross Sectional Study ◽  
Performance Characteristics ◽  
Sectional Study ◽  
Cross Sectional

scholarly journals Trainee colonoscopy quality is influenced by the independent and unobserved performance characteristics of supervising physicians

2019 ◽  
Vol 07 (01) ◽  
pp. E74-E82 ◽  
Author(s):  
Srihari Mahadev ◽  
Zhezhen Jin ◽  
Benjamin Lebwohl ◽  
Richard Rosenberg ◽  
Reuben Garcia-Carrasquillo ◽  
...  
Keyword(s):  
Role Models ◽  
Medical Center ◽  
Academic Medical Center ◽  
Cross Sectional Study ◽  
Performance Characteristics ◽  
Withdrawal Time ◽  
Cross Sectional ◽  
Endoscopy Training ◽  
Adenoma Detection

Abstract Background Endoscopy training remains an apprenticeship, and the characteristics that facilitate transfer of high quality procedural skills from role models to trainees are unknown. We sought to determine whether unobserved supervisor performance influences the quality of colonoscopy performed by trainees, by studying how supervisors perform alone and how trainees perform while under those same supervisors. Methods This was a retrospective cross-sectional study conducted among ambulatory adults ≥ 50 years old who underwent colonoscopy for cancer screening or polyp surveillance from 2006 to 2015 at one academic medical center. The primary exposures were the colonoscopy withdrawal time (WT) and adenoma detection rate (ADR) of supervisors while performing colonoscopies alone. The primary outcomes were the WT and ADR of trainees performing colonoscopies under supervision. Results Data were included from 22 attending gastroenterologist supervisors, 56 gastroenterology fellow trainees, and 2777 adults undergoing 3094 colonoscopy procedures. Among all supervised colonoscopies, mean trainee WT was 12.7 minutes (SD 4.9) and trainee ADR was 33.5 %. The trainee WT was 0.42 minutes longer (standard error = 0.16, P = 0.01) per minute increase in supervisor WT. Similarly, trainee ADR was higher under a high ADR supervisor, and the odds ratio of high compared to low supervisor ADR category was 1.28 (95 %CI 1.01 – 1.62, P = 0.04) after adjusting for other factors. Conclusions The unobserved performance characteristics of supervising endoscopists may influence the quality of colonoscopy performed by trainees.

scholarly journals Performance of the Maxim and Sedia Limiting Antigen Avidity assays for population-level HIV incidence surveillance

2019 ◽  
Author(s):  
Joseph B. Sempa ◽  
Alex Welte ◽  
Michael P. Busch ◽  
Jake Hall ◽  
Dylan Hampton ◽  
...  
Keyword(s):  
Viral Load ◽  
Population Level ◽  
Performance Characteristics ◽  
Recent Infection ◽  
Cross Sectional ◽  
Repeat Testing ◽  
Incidence Estimation ◽  
Treatment Naïve ◽  
Context Specific ◽  
Hiv 1

AbstractBackgroundTwo manufacturers, Maxim Biomedical and Sedia Biosciences Corporation, supply US CDC-approved versions of the HIV-1 Limiting Antigen Avidity EIA (LAg assay) for detecting ‘recent’ HIV infection in cross-sectional incidence estimation. This study assesses and compares the performance of the Maxim and Sedia LAg assays for incidence surveillance.MethodsWe ran both assays on a panel of 2,500 well-characterized HIV-1-infected specimens, most with estimated dates of (detectable) infection. We analysed concordance of assay results, assessed reproducibility using repeat testing and estimated the critical performance characteristics of a test for recent infection—mean duration of recent infection (MDRI) and false-recent rate (FRR)—for a range of normalized optical density (ODn) recency discrimination thresholds, alone and in combination with viral load thresholds. We further defined three hypothetical surveillance scenarios and evaluated overall performance for incidence surveillance, defined as the precision of incidence estimates, by estimating context-specific performance characteristics.ResultsThe Maxim assay produced lower ODn values than the Sedia assay on average, largely as a result of higher calibrator readings (mean calibrator OD of 0.749 vs. 0.643). Correlation of non-normalized OD readings was greater (R2 = 0.938) than those of ODn readings (R2 = 0.908), and the slope was closer to unity (1.054 vs. 0.899). Reproducibility of repeat testing of three blinded control specimens (25 replicates each) was slightly better for the Maxim assay (CV 8.9% to 14.8% vs. 13.2% to 15.0%). The MDRI of a Maxim-based algorithm at the ‘standard’ recency discrimination threshold in combination with viral load (ODn ≤1.5 & VL >1,000) was 201 days (95% CI: 180,223) and for Sedia was 171 days (95% CI: 152,191). Commensurately, the Maxim algorithm had a higher FRR in treatment-naive subjects (1.7% vs. 1.1%). We observed statistically significant differences in MDRI using the ODn alone (≤1.5) and in combination with viral load (>1,000). Under three fully-specified hypothetical surveillance scenarios (comparable to South Africa, Kenya and a concentrated epidemic), recent infection testing algorithms based on the two assays produced similar precision of incidence estimates.ConclusionsDifferences in ODn measurements between the Maxim and Sedia LAg assays on the same specimens largely resulted from differences in the reactivity of calibrators supplied by the manufacturers. Performance for surveillance purposes was extremely similar, although different ODn thresholds were optimal and different values of MDRI and FRR were appropriate for use in survey planning and incidence estimation.

Automated Image Analysis Of Nuclear And Cytoplasmic Changes In Exfoliated Cells From Tracheas Treated With Carcinogen

1977 ◽  
Vol 35 ◽  
pp. 220-221
Author(s):  
S.F. Stinson ◽  
J.C. Lilga ◽  
M.B. Sporn
Keyword(s):  
Image Analysis ◽  
Pattern Analysis ◽  
Relative Proportion ◽  
Automated Image Analysis ◽  
Image Analyzer ◽  
Cross Sectional ◽  
Exfoliated Cells ◽  
Neoplastic Lesions ◽  
Analysis System ◽  
Morphologic Criterion

Increased nuclear size, resulting in an increase in the relative proportion of nuclear to cytoplasmic sizes, is an important morphologic criterion for the evaluation of neoplastic and pre-neoplastic cells. This paper describes investigations into the suitability of automated image analysis for quantitating changes in nuclear and cytoplasmic cross-sectional areas in exfoliated cells from tracheas treated with carcinogen.Neoplastic and pre-neoplastic lesions were induced in the tracheas of Syrian hamsters with the carcinogen N-methyl-N-nitrosourea. Cytology samples were collected intra-tracheally with a specially designed catheter (1) and stained by a modified Papanicolaou technique. Three cytology specimens were selected from animals with normal tracheas, 3 from animals with dysplastic changes, and 3 from animals with epidermoid carcinoma. One hundred randomly selected cells on each slide were analyzed with a Bausch and Lomb Pattern Analysis System automated image analyzer.

X-Ray Replication of Submicrometer Linewidth Patterns

1977 ◽  
Vol 35 ◽  
pp. 136-137
Author(s):  
Henry I. Smith ◽  
D.C. Flanders
Keyword(s):  
Electron Beam Lithography ◽  
Cross Sectional ◽  
X Ray ◽  
Electron Backscattering ◽  
Spatial Frequencies ◽  
Cross Sectional Profile ◽  
Carbon Foils ◽  
Sectional Profile ◽  
And Control ◽  
Soft Radiation

Scanning electron beam lithography has been used for a number of years to write submicrometer linewidth patterns in radiation sensitive films (resist films) on substrates. On semi-infinite substrates, electron backscattering severely limits the exposure latitude and control of cross-sectional profile for patterns having fundamental spatial frequencies below about 4000 Å(l),Recently, STEM'S have been used to write patterns with linewidths below 100 Å. To avoid the detrimental effects of electron backscattering however, the substrates had to be carbon foils about 100 Å thick (2,3). X-ray lithography using the very soft radiation in the range 10 - 50 Å avoids the problem of backscattering and thus permits one to replicate on semi-infinite substrates patterns with linewidths of the order of 1000 Å and less, and in addition provides means for controlling cross-sectional profiles. X-radiation in the range 4-10 Å on the other hand is appropriate for replicating patterns in the linewidth range above about 3000 Å, and thus is most appropriate for microelectronic applications (4 - 6).

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