A unique drone design promises aircraft payload with helicopter precision

A study of two forest ecosystems in Spain has found that land-cover maps of watersheds, ecosystems hosting key interactions between vegetation, wildlife, and water, are made more accurate by the inclusion of LiDAR data — a type of remote sensing that pulses laser light at a target to measure vertical distances for use in 3D-mapping an environment. This has important implications for ecosystem monitoring, flood mitigation, and forest management, fields in which accurately characterising an environment is key.

Economic valuation of ecosystem services, from good quality water supplies to cooling cities in the face of climate change, can provide vital information for policy decisions. However, the definition and interpretation of ecosystem services need to be clarified to ensure accurate valuations, suggests new research.

In conversation with ETCIO, Subodh Kumar, CTO, Magicbricks, shares how data comprising 75 attributes has helped the company generate 60% more quality leads

With better address data, the city added more than 300 missing addresses to the Census file provided by the federal government

Research Highlights: Most home blood pressure monitoring devices sold in Australia by global e-commerce sites such as Amazon and eBay have not been validated (tested for accuracy). Using an unvalidated device could lead to incorrect at-home blood...

Tags: coronavirus, Quartz, testing, uncertainity

A method and system for optical proximity correction (OPC) is disclosed in which a set of shaped beam shots is determined which, when used in a shaped beam charged particle beam writer, will form a pattern on a reticle, where some of the shots overlap, where the pattern on the reticle is an OPC-corrected version of an input pattern, and where the sensitivity of the pattern on the reticle to manufacturing variation is reduced. A method for fracturing or mask data preparation is also disclosed.

Precision AC and DC voltage, current, phase, power and energy measurements and calibrations with current ranges from 1 uA to 20 kA and voltage ranges from 1V to 1000 kV are now performed with accuracies of better than one part per million. Continued demand for improved accuracy has led the inventors to address remnant magetization within the current comparators that form the basis of the measuring process within many of the measurement instruments providing the precision AC and DC measurements and calibrations. Accordingly, the inventors present current comparator and measurement system architectures together with control protocols to provide for correction of this remnant magnetization.

Boston-based MIT Media Lab spinoff Formlabs has today launched two new 3D printers at the Additive Manufacturing Users Group (AMUG) show in Chicago

Amelia C. Peterson
Nov 1, 2012; 11:1475-1488
Technological Innovation and Resources

Ivan Matic
Jan 1, 2008; 7:132-144
Research

Jesper V. Olsen
Dec 1, 2005; 4:2010-2021
Technology

Due to improvements in quantitative SPECT/CT, voxel-based dosimetry for radionuclide therapies has aroused growing interest as it promises the visualization of absorbed doses at a voxel level. In this work, SPECT/CT-based voxel-based dosimetry of a 3D printed 2-compartment kidney phantom was performed, and the resulting absorbed dose distributions were examined. Additionally, the potential of the PETPVC partial-volume correction tool was investigated. Methods: Both kidney compartments (70% cortex, 30% medulla) were filled with different activity concentrations and SPECT/CT imaging was performed. The images were reconstructed using varying reconstruction settings (iterations, subsets, and post-filtering). Based on these activity concentration maps, absorbed dose distributions were calculated with pre-calculated ¹⁷⁷Lu voxel S values and an empirical kidney half-life. An additional set of absorbed doses was calculated after applying PETPVC for partial-volume correction of the SPECT reconstructions. Results: SPECT/CT imaging blurs the two discrete sub-organ absorbed dose values into a continuous distribution. While this effect is slightly improved by applying more iterations, it is enhanced by additional post-filtering. By applying PETPVC, the absorbed dose values are separated into 2 peaks. Although this leads to a better agreement between SPECT/CT-based and nominal values, considerable discrepancies remain. In contrast to the calculated nominal absorbed doses of 7.8/1.6 Gy (cortex/medulla), SPECT/CT-based voxel-level dosimetry resulted in mean absorbed doses ranging from 3.0-6.6 Gy (cortex) and 2.7-5.1 Gy (medulla). PETPVC led to improved ranges of 6.1-8.9 Gy (cortex) and 2.1-5.4 Gy (medulla). Conclusion: Our study shows that ¹⁷⁷Lu quantitative SPECT/CT imaging leads to voxel-based dose distributions largely differing from the real organ distribution. SPECT/CT imaging and reconstruction deficiencies might directly translate into unrealistic absorbed dose distributions, thus questioning the reliability of SPECT-based voxel-level dosimetry. Therefore, SPECT/CT reconstructions should be adapted to ensure an accurate quantification of the underlying activity and, therefore, absorbed dose in a volume-of-interest of the expected object size (e.g. organs, organ sub-structures, lesions or voxels). As an example, PETPVC largely improves the match between SPECT/CT-based and nominal dose distributions. In conclusion, the concept of voxel-based dosimetry should be treated with caution. Specifically, it should be kept in mind that the absorbed dose distribution is mainly a convolved version of the underlying SPECT reconstruction.

Teng-Fei Yuan
Apr 1, 2020; 61:580-586
Methods

Analyzing global steroid metabolism in humans can shed light on the etiologies of steroid-related diseases. However, existing methods require large amounts of serum and lack the evaluation of accuracy. Here, we developed an LC/MS/MS method for the simultaneous quantification of 12 steroid hormones: testosterone, pregnenolone, progesterone, androstenedione, corticosterone, 11-deoxycortisol, cortisol, 17-hydroxypregnenolone, 17-hydroxyprogesterone, dehydroepiandrosterone, estriol, and estradiol. Steroids and spiked internal standards in 100 μl serum were extracted by protein precipitation and liquid-liquid extraction. The organic phase was dried by evaporation, and isonicotinoyl chloride was added for steroid derivatization, followed by evaporation under nitrogen and redissolution in 50% methanol. Chromatographic separation was performed on a reverse-phase PFP column, and analytes were detected on a triple quadrupole mass spectrometer with ESI. The lower limits of quantification ranged from 0.005 ng/ml for estradiol to 1 ng/ml for cortisol. Apparent recoveries of steroids at high, medium, and low concentrations in quality control samples were between 86.4% and 115.0%. There were limited biases (–10.7% to 10.5%) between the measured values and the authentic values, indicating that the method has excellent reliability. An analysis of the steroid metabolome in pregnant women highlighted the applicability of the method in clinical serum samples. We conclude that the LC/MS/MS method reported here enables steroid metabolome analysis with high accuracy and reduced serum consumption, indicating that it may be a useful tool in both clinical and scientific laboratory research.

Posttreatment high-grade gliomas are usually monitored with contrast-enhanced MRI, but its diagnostic accuracy is limited as it cannot adequately distinguish between true tumor progression and treatment-related changes. According to recent Response Assessment in Neuro-Oncology recommendations, PET overcomes this limitation. However, it is currently unknown which tracer yields the best results. Therefore, a systematic review and metaanalysis were performed to compare the diagnostic accuracy of the different PET tracers in differentiating tumor progression from treatment-related changes in high-grade glioma patients. Methods: PubMed, Web of Science, and Embase were searched systematically. Study selection, data extraction, and quality assessment were performed independently by 2 authors. Metaanalysis was performed using a bivariate random-effects model when at least 5 studies were included. Results: The systematic review included 39 studies (11 tracers). ¹⁸F-FDG (12 studies, 171 lesions) showed a pooled sensitivity and specificity of 84% (95% confidence interval, 72%–92%) and 84% (95% confidence interval, 69%–93%), respectively. O-(2-¹⁸F-fluoroethyl)-l-tyrosine (¹⁸F-FET) (7 studies, 172 lesions) demonstrated a sensitivity of 90% (95% confidence interval, 81%–95%) and specificity of 85% (95% confidence interval, 71%–93%). For S-¹¹C-methyl)-l-methionine (¹¹C-MET) (8 studies, 151 lesions), sensitivity was 93% (95% confidence interval, 80%–98%) and specificity was 82% (95% confidence interval, 68%–91%). The numbers of included studies for the other tracers were too low to combine, but sensitivity and specificity ranged between 93%–100% and 0%–100%, respectively, for ¹⁸F-FLT; 85%–100% and 72%–100%, respectively, for 3,4-dihydroxy-6-¹⁸F-fluoro-l-phenylalanine (¹⁸F-FDOPA); and 100% and 70%–88%, respectively, for ¹¹C-choline. Conclusion: ¹⁸F-FET and ¹¹C-MET, both amino-acid tracers, showed a comparably higher sensitivity than ¹⁸F-FDG in the differentiation between tumor progression and treatment-related changes in high-grade glioma patients. The evidence for other tracers is limited; thus, ¹⁸F-FET and ¹¹C-MET are preferred when available. Our results support the incorporation of amino-acid PET tracers for the treatment evaluation of high-grade gliomas.

William L Clarke
Sep 1, 1987; 10:622-628
Technical Article

David C. Klonoff
Aug 1, 2018; 41:1681-1688
Emerging Technologies: Data Systems and Devices

Primary care providers (PCPs) identify patients with undescended testis (UDT) and refer them to surgical specialists. Referral beyond the recommended times for orchiopexy has been reported, and PCPs' accuracy in identifying and distinguishing UDTs from retractile testes has been questioned.

We describe 3 observations that are strongly correlated with UDT, that is, birth history of UDT, prematurity, and visible scrotal asymmetry. UDT diagnoses are best made by 8 months of age, to reduce confusion with testicular retraction and to facilitate timely orchiopexy. (Read the full article)

Healthcare Effectiveness Data and Information Set (HEDIS) measures are widely used to assess the reliability of pediatric immunization delivery. The extent to which these measures provide accurate ("is this child up-to-date on immunizations?") and useful ("is this child due for catch-up immunizations?") information is unclear.

Overall, HEDIS childhood immunization measures are accurate and useful. Users of HEDIS data should be aware, however, that certain immunizations (eg, hepatitis B, pneumococcal conjugate) and children (eg, those with a single overdue immunization) are more prone to HEDIS misclassification. (Read the full article)

Because pediatric appendicitis is challenging to diagnose, computed tomography (CT) is used frequently. Childhood radiation exposure is associated with increased risk of cancer. Ultrasound avoids radiation exposure but is less sensitive for appendicitis than CT.

Controlling for referral bias, evaluation at a community compared with a children’s hospital is associated with higher CT and lower ultrasound use before appendectomy. CT and ultrasound accuracy for appendicitis in children varies with hospital type. (Read the full article)

Head injuries and concern for skull fracture are common in pediatrics. Point-of-care ultrasound is an imaging tool that can be used to diagnose fractures. However, there are scant data regarding the accuracy of point-of-care ultrasound in skull fracture diagnosis.

Clinicians with focused point-of-care ultrasound training are able to diagnose skull fractures in children with high specificity. Ultrasound may be valuable to diagnose skull fractures in children at the point of care. (Read the full article)

Children with chronic illnesses tend to be sicker during infections than previously healthy children but are triaged in the same way, even though the validity of triage systems has not yet been evaluated in these chronically sick children.

The performance of the Manchester Triage System was lower for children with a chronic illness than for previously healthy children. Children with cardiovascular illnesses, respiratory illnesses, gastrointestinal illnesses, or other congenital or genetic defects were especially at risk of being undertriaged. (Read the full article)

Saturations from pulse oximetry (SpO₂) may overestimate arterial oxygen saturations measured by CO-oximetry (SaO₂). The overestimation can be affected by location of measurement, perfusion, and skin color. Previous studies are limited by small numbers of observations in a hypoxemic range.

This large sample of hypoxemic patients identified that SpO₂ typically overestimates SaO₂. Bias and precision varied throughout the SpO₂ range. The SpO₂ range of 81% to 85% had the greatest bias: median SpO₂ 6% higher than SaO₂ measured by CO-oximetry. (Read the full article)

Studies assessing the accuracy of brief screening tools for postpartum depression have been conducted among adult women; however, no similar validation studies have been conducted among adolescent mothers. Accurate and valid brief depression screening tools are needed for adolescent mothers.

We found that the 10-item Edinburgh Postnatal Depression Scale (EPDS) and 2 subscales, the EPDS-7 and EPDS-2, are highly accurate at identifying postpartum depression among adolescent mothers. In pediatric settings with limited time and resources, these brief scales have potential to be used as effective depression screening tools. (Read the full article)

The sensitivities of ^99mTc-dimercaptosuccinic acid in predicting vesicoureteral reflux reported by different institutions were at different levels for young children with acute febrile urinary tract infection.

An acute ^99mTc-dimercaptosuccinic acid scan is of great value in predicting dilating vesicoureteral reflux in children ≤2 years of age with a febrile urinary tract infection. (Read the full article)

The sensitivity of the urinalysis (UA) traditionally has been considered suboptimal in young infants. Whether the finding of a negative UA and a positive urine culture represents a false-negative UA versus a false-positive urine culture remains unclear.

In infants <3 months with bacteremic urinary tract infection, a condition that represents true infection, the UA sensitivity is higher than previously reported for urinary tract infection in general, suggesting that the UA is reliable even in young infants. (Read the full article)

The tests could reveal the true extent of the outbreak and help separate the healthy from the sick. But some scientists have challenged their accuracy.

Many noncoding RNAs are known to play a role in the cell directly linked to their structure. Structure prediction based on the sole sequence is, however, a challenging task. On the other hand, thanks to the low cost of sequencing technologies, a very large number of homologous sequences are becoming available for many RNA families. In the protein community, the idea of exploiting the covariance of mutations within a family to predict the protein structure using the direct-coupling-analysis (DCA) method has emerged in the last decade. The application of DCA to RNA systems has been limited so far. We here perform an assessment of the DCA method on 17 riboswitch families, comparing it with the commonly used mutual information analysis and with state-of-the-art R-scape covariance method. We also compare different flavors of DCA, including mean-field, pseudolikelihood, and a proposed stochastic procedure (Boltzmann learning) for solving exactly the DCA inverse problem. Boltzmann learning outperforms the other methods in predicting contacts observed in high-resolution crystal structures.

In patients with cancer-associated venous thromboembolism, knowledge of the estimated rate of recurrent events is important for clinical decision-making regarding anticoagulant therapy. The Ottawa score is a clinical prediction rule designed for this purpose, stratifying patients according to their risk of recurrent venous thromboembolism during the first six months of anticoagulation. We conducted a systematic review and meta-analysis of studies validating either the Ottawa score in its original or modified versions. Two investigators independently reviewed the relevant articles published from 1st June 2012 to 15th December 2018 and indexed in MEDLINE and EMBASE. Nine eligible studies were identified; these included a total of 14,963 patients. The original score classified 49.3% of the patients as high-risk, with a sensitivity of 0.7 [95% confidence interval (CI): 0.6-0.8], a 6-month pooled rate of recurrent venous thromboembolism of 18.6% (95%CI: 13.9-23.9). In the low-risk group, the recurrence rate was 7.4% (95%CI: 3.4-12.5). The modified score classified 19.8% of the patients as low-risk, with a sensitivity of 0.9 (95%CI: 0.4-1.0) and a 6-month pooled rate of recurrent venous thromboembolism of 2.2% (95%CI: 1.6-2.9). In the high-risk group, recurrence rate was 10.2% (95%CI: 6.4-14.6). Limitations of our analysis included type and dosing of anticoagulant therapy. We conclude that new therapeutic strategies are needed in patients at high risk for recurrent cancer-associated venous thromboembolism. Low-risk patients, as per the modified score, could be good candidates for oral anticoagulation. (This systematic review was registered with the International Prospective Registry of Systematic Reviews as: PROSPERO CRD42018099506).

Recognizing that guideline-directed histologic grading of endomyocardial biopsy tissue samples for rejection surveillance has limited diagnostic accuracy, quantitative, in situ characterization was performed of several important immune cell types in a retrospective cohort of clinical endomyocardial tissue samples. Differences between cases were identified and were grouped by histologic grade versus clinical rejection trajectory, with significantly increased programmed death ligand 1+, forkhead box P3+, and cluster of differentiation 68+ cells suppressed in clinically evident rejections, especially cases with marked clinical-histologic discordance. Programmed death ligand 1+, forkhead box P3+, and cluster of differentiation 68+ cell proportions are also significantly higher in "never-rejection" when compared with "future-rejection." These findings suggest that in situ immune modulators regulate the severity of cardiac allograft rejection.

Background:

Colonoscopy follow-up recommendations depend on the presence or absence of polyps, and if found, their number, size, and histology. Patients may be responsible for conveying results between primary and specialty care or providing medical information to family members; thus, accurate reporting is critical. This analysis assessed the accuracy of self-reported colonoscopy findings.

UK scientists have developed a new coronavirus antibody test which they say produces results in 35 minutes with 99.8 per cent accuracy.

Antibody tests at 98 per cent accuracy would put up to a quarter of population at risk of infection, government advisers have warned.

It's the most accurate one yet

Expanding coronavirus testing is one of the most important tasks public health officials are tackling right now. But questions over accuracy of the two main types of tests have rightly caused concern.

Authors of a new study say dogs may help develop over-the-counter tests capable of life-saving early detection.

Nearly one out of three times, women considering abortion in the States get medically inaccurate information that usually requires a doctor to provide

JT Lewis, whose six-year-old brother Jesse was one of the 26 people killed in the Connecticut mass shooting, eviscerated the 2020 hopeful for making the claim in a new video released earlier this week.

JT Lewis, whose six-year-old brother Jesse was one of the 26 people killed in the Connecticut mass shooting, eviscerated the 2020 hopeful for making the claim in a new video released earlier this week.

World No 2 Rafael Nadal likes a challenge and he wowed the crowd at the US Open after hitting a tennis ball into the window of a TV studio from the Arthur Ashe stadium court.

Barker Library - TA357.5.D37 S46 2013

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