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Nevin Manimala Statistics

Science and Statistics

Diving Hyperb Med. 2021 Jun 30;51(2):230. doi: 10.28920/dhm51.2.230.

NO ABSTRACT

PMID:34157744 | DOI:10.28920/dhm51.2.230

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Nevin Manimala Statistics

Semiquantitative Criteria in the Eye Bank That Correlate with Cornea Guttata in Donor Corneas

Klin Monbl Augenheilkd. 2021 Jun;238(6):680-687. doi: 10.1055/a-1498-1846. Epub 2021 Jun 22.

ABSTRACT

BACKGROUND: Cornea guttata may not be recognized in the eye bank and recent studies have displayed that guttae are transplanted in about 15% of cases in varying severities. The purpose of this study was to establish semiquantitative criteria for the detection of cornea guttata in donor corneas in the eye bank.

METHODS: In this retrospective cohort study, preoperative endothelial pictures of donor corneas were collected and classified according to the post-penetrating keratoplasty cornea guttata grade into three distinct groups: group 1 consists of healthy corneas with no guttae (guttata grade 0); group 2 constitutes corneas with mild asymptomatic cornea guttata (guttata grade +); and group 3 comprises corneas with advanced widespread cornea guttata (guttata grade ++/+++/++++). The preoperative pictures of each group were then individually analyzed using the following five semiquantitative criteria: The number and the area of the cell-depleted surfaces, the presence of less than 50% of the cells having a hexagonal or a circular shape, the presence of cell membrane defects and interruptions, the presence of blebs in the cell membrane, and the presence of groups of cells with a distinct whitish color.

RESULTS: In total, 262 patients were included in this study, with a total number of 1582 preoperative donor corneal endothelial pictures. Out of those pictures, groups 1, 2, and 3 encompassed 995 (62.9%), 411 (26.0%), and 176 (11.1%) pictures, respectively. Three out of the five eye bank criteria were found to correlate with postoperative cornea guttata with a highly significant p value of < 0.001. These three criteria are the presence of less than 50% of the cells having a hexagonal or a circular shape, the presence of cell membrane defects and interruptions and, the presence of blebs. The presence of groups of cells with a distinct whitish color was only a weak predictive factor for cornea guttata (p = 0.069). There was no statistically significant correlation between the number and the area of cell-depleted surfaces and postoperative cornea guttata with a p = 0.181.

CONCLUSION: Three semiquantitative criteria that can be detected in the eye bank using inverted light microscopy seem to correlate with postoperative cornea guttata: The presence of blebs, the presence of cell membrane defects and interruptions, as well as endothelial pictures with less than 50% of the cells having a hexagonal of circular shape. The presence of groups of cells with a distinct whitish color appears to be a weak predictor of cornea guttata.

PMID:34157770 | DOI:10.1055/a-1498-1846

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Nevin Manimala Statistics

Cost Burden and Cost-Effective Analysis of the Nationwide Implementation of the Quality in Acute Stroke Care Protocol in Australia

J Stroke Cerebrovasc Dis. 2021 Jun 19;30(8):105931. doi: 10.1016/j.jstrokecerebrovasdis.2021.105931. Online ahead of print.

ABSTRACT

OBJECTIVES: The Quality in Acute Stroke Care (QASC) protocol is a multidisciplinary approach to implement evidence-based treatment after acute stroke that reduces death and disability. This study sought to evaluate the cost-effectiveness of implementing the QASC protocol across Australia, from a healthcare and a societal perspective.

MATERIALS AND METHODS: A decision-analytic model was constructed to reflect one-year outcomes post-stroke, aligned with the stroke severity categories of the modified Rankin scale (mRS). Decision analysis compared outcomes following implementation of the QASC protocol versus no implementation. Population data were extracted from Australian databases and data inputs regarding stroke incidence, costs, and utilities were drawn from published sources. The analysis assumed a progressive uptake and efficacy of the QASC protocol over five years. Health benefits and costs were discounted by 5% annually. The cost of each year lived by an Australian, from a societal perspective, was based on the Australian Government’s ‘value of statistical life year’ (AUD 213,000).

RESULTS: Over five years, the model predicted 263,722 strokes among the Australian population. The implementation of the QASC protocol was predicted to prevent 1,154 deaths and yield a gain of 876 years of life (0.003 per stroke), and 3,180 quality-adjusted life years (QALYs) (0.012 per stroke). There was an estimated net saving of AUD 65.2 million in healthcare costs (AUD 247 per stroke) and AUD 251.7 million in societal costs (AUD 955 per stroke).

CONCLUSIONS: Implementation of the QASC protocol in Australia represents both a dominant (cost-saving) strategy, from a healthcare and a societal perspective.

PMID:34157669 | DOI:10.1016/j.jstrokecerebrovasdis.2021.105931

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Nevin Manimala Statistics

A methodology to estimate the patient diameter and thickness from thoracic and abdominal projection radiographs of adult patients

Phys Med Biol. 2021 Jun 22. doi: 10.1088/1361-6560/ac0d8c. Online ahead of print.

ABSTRACT

Patient dose management systems can be part of a department’s quality management tools to estimate items such as the radiation burden in specific groups or list dose outliers for further follow up. Patient size information could improve both aspects, but is not generally available. A new metric is proposed to estimate patient size for thorax and abdominal projection radiography from parameters available in the DICOM header and therefore accessible by dose management software. The tested hypothesis was that an attenuation metric, related to the ratio of detector air-kerma to incident air-kerma, inversely correlates with patient size. Such a metric was defined and then worked out for thorax and abdomen projection radiography. Input material consisted of the thorax or abdominal radiographs of 137 cases, completed with a recent CT scan as ground truth size. From the CT, the water equivalent diameter and water equivalent thickness were calculated. The correlation between the attenuation metric and the patient size was established separately for thorax and abdomen. Validation of the attenuation metric predicting the patient size was performed using extra sets of examinations on three more radiographic x-ray devices, with available CT scan. The attenuation metric had a good correlation (R2) of 0.91 and 0.84 with the water equivalent diameter for thorax and abdomen respectively. The corresponding values for the water equivalent thickness were 0.89 and 0.78. Validation of the methodology on the devices with standardized exposure index in the DICOM headers showed that the water equivalent diameter could be estimated within ±15% and the water equivalent thickness within ±30% for thorax and abdomen examinations. The ground truth and estimated size were found statistically equivalent. An attenuation metric based on DICOM tags allows to estimate the patient size in projection radiography. This could now be implemented in patient dose management systems.

PMID:34157703 | DOI:10.1088/1361-6560/ac0d8c

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Nevin Manimala Statistics

Oxygen toxicity seizures during United States Navy Treatment Table 6: An acceptable risk in monoplace chambers?

Diving Hyperb Med. 2021 Jun 30;51(2):167-172. doi: 10.28920/dhm51.2.167-172.

ABSTRACT

INTRODUCTION: Hyperbaric oxygen treatment (HBOT) may be complicated by oxygen toxicity seizures, which typically occur with hyperbaric partial pressures of oxygen exceeding 203 kPa (2 atmospheres absolute). All other hyperbaric units in Australia exclusively use a multiplace chamber when treating with United States Navy Treatment Table 6 (USN TT6) due to this perceived risk. The purpose of this study was to determine the safety of a monoplace chamber when treating decompression illness (DCI) with USN TT6.

METHODS: A retrospective review of the medical records of all patients treated at Fiona Stanley Hospital Hyperbaric Medicine Unit with USN TT6 between November 2014 and June 2020 was undertaken. These data were combined with previous results from studies performed at our hyperbaric unit at Fremantle Hospital from 1989 to 2014, creating a data set covering a 30-year period.

RESULTS: One thousand treatments with USN TT6 were performed between 1989 and 2020; 331 in a monoplace chamber and 669 in a multiplace chamber. Four seizures occurred: a rate of 0.59% (1/167) in a multiplace chamber; and none in a monoplace chamber, indicating no statistically significant difference between seizures in a monoplace versus multiplace chamber (P = 0.31).

CONCLUSIONS: The rate of oxygen toxicity seizures in a monoplace chamber is not significantly higher than for treatment in the multiplace chamber. We conclude that using the monoplace chamber for USN TT6 in selected patients poses an acceptably low seizure risk.

PMID:34157732 | DOI:10.28920/dhm51.2.167-172

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Nevin Manimala Statistics

Deep learning-based automated detection of pulmonary embolism on CT pulmonary angiograms: No significant effects on report communication times and patient turnaround in the emergency department nine months after technical implementation

Eur J Radiol. 2021 Jun 11;141:109816. doi: 10.1016/j.ejrad.2021.109816. Online ahead of print.

ABSTRACT

OBJECTIVES: Rapid communication of CT exams positive for pulmonary embolism (PE) is crucial for timely initiation of anticoagulation and patient outcome. It is unknown if deep learning automated detection of PE on CT Pulmonary Angiograms (CTPA) in combination with worklist prioritization and an electronic notification system (ENS) can improve communication times and patient turnaround in the Emergency Department (ED).

METHODS: In 01/2019, an ENS allowing direct communication between radiology and ED was installed. Starting in 10/2019, CTPAs were processed by a deep learning (DL)-powered algorithm for detection of PE. CTPAs acquired between 04/2018 and 06/2020 (n = 1808) were analysed. To assess the impact of the ENS and the DL-algorithm, radiology report reading times (RRT), radiology report communication time (RCT), time to anticoagulation (TTA), and patient turnaround times (TAT) in the ED were compared for three consecutive time periods. Performance measures of the algorithm were calculated on a per exam level (sensitivity, specificity, PPV, NPV, F1-score), with written reports and exam review as ground truth.

RESULTS: Sensitivity of the algorithm was 79.6 % (95 %CI:70.8-87.2%), specificity 95.0 % (95 %CI:92.0-97.1%), PPV 82.2 % (95 %CI:73.9-88.3), and NPV 94.1 % (95 %CI:91.4-96 %). There was no statistically significant reduction of any of the observed times (RRT, RCT, TTA, TAT).

CONCLUSION: DL-assisted detection of PE in CTPAs and ENS-assisted communication of results to referring physicians technically work. However, the mere clinical introduction of these tools, even if they exhibit a good performance, is not sufficient to achieve significant effects on clinical performance measures.

PMID:34157638 | DOI:10.1016/j.ejrad.2021.109816

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Nevin Manimala Statistics

Periodicity and multi-periodicity generated by impulses control in delayed Cohen-Grossberg-type neural networks with discontinuous activations

Neural Netw. 2021 Jun 15;143:230-245. doi: 10.1016/j.neunet.2021.06.013. Online ahead of print.

ABSTRACT

This paper discusses the periodicity and multi-periodicity in delayed Cohen-Grossberg-type neural networks (CGNNs) possessing impulsive effects, whose activation functions possess discontinuities and are allowed to be unbounded or nonmonotonic. Based on differential inclusion and cone expansion-compression fixed-point theory of set-valued mapping, several improved criteria are given to derive the positive solution with ω-periodicity and ω-multi-periodicity for delayed CGNNs under impulsive control. These ω-periodicity/ω-multi-periodicity orbits are produced by impulses control. The analytical method and theoretical results presented in this paper are of certain significance to the design of neural network models or circuits possessing discontinuous neuron activation and impulsive effects in periodic environment.

PMID:34157647 | DOI:10.1016/j.neunet.2021.06.013

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Nevin Manimala Statistics

Estimation of komatsuna freshness using visible and near-infrared spectroscopy based on the interpretation of NMR metabolomics analysis

Food Chem. 2021 Jun 16;364:130381. doi: 10.1016/j.foodchem.2021.130381. Online ahead of print.

ABSTRACT

The objective of this study was to explore the potentiality and mechanism of visible and near-infrared (Vis-NIR) spectroscopy in estimating the freshness of komatsuna. We monitored the cumulative CO2 production of komatsuna stored under different conditions as a freshness indicator and measured the Vis-NIR spectra of komatsuna as the predictor. Using the informative wavelengths (IW) selected using the stepwise selectivity ratio method, we constructed an accurate freshness prediction model through PLSR analysis. The IW in the visible region were attributed to pigments such as chlorophyll. In the NIR region, ten amino acids were identified as directly or indirectly contributing to the IW and were highly related to freshness. They were confirmed on the basis of the strong correlations between the informative NIR signals and NMR signals, which were determined using statistical heterospectroscopy. The results demonstrate the feasibility of Vis-NIR spectroscopy in estimating the freshness of komatsuna using the IW.

PMID:34157592 | DOI:10.1016/j.foodchem.2021.130381

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Nevin Manimala Statistics

Influence of soil quality factors on capsaicin biosynthesis, pungency, yield, and produce quality of chili: An insight on Csy1, Pun1, and Pun12 signaling responses

Plant Physiol Biochem. 2021 Jun 16;166:427-436. doi: 10.1016/j.plaphy.2021.06.012. Online ahead of print.

ABSTRACT

Hotness or pungency is the major trait of genetically diverse and economically valuable chili (Capsicum sp.) cultivars. However, little is known about the influence of soil characteristics on genetic regulation of pungency vis-à-vis capsaicin formation in endemic chilies. Hence, the present work was conducted by growing two endemic chili cultivars in two types (alluvial and lateritic) of soil. Capsaicin content, pungency, and capsaicin synthase activity were significantly greater in chilies grown in alluvial soil than in lateritic soil. Correspondingly, Csy1, the gene that encodes capsaicin synthase, was significantly upregulated in alluvial soil grown plants. Interestingly, upregulation of Pun1, the gene responsible for capsaicin accumulation in fruits, was more in lateritic soil than in alluvial soil; but pungency was inhibited in lateritic soil by the overexpression of Pun12, a recessive allele of Pun1 locus. Statistical analyses revealed that high organic C, microbial activity, and NPK status in alluvial soil were responsible for high pungency, capsaicin synthase activity, capsaicin accumulation, and suppression of Pun12. Fruit yield, dry matter, crude protein, titratable acidity, and soluble solids were also significantly high in chilies grown in alluvial soil. Therefore, we postulate that soil quality attributes play vital roles in genetic regulation of pungency, capsaicin biosynthesis, fruit yield, and produce quality of endemic chili cultivars.

PMID:34157605 | DOI:10.1016/j.plaphy.2021.06.012

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Nevin Manimala Statistics

Phase 1 dose-escalation and pharmacokinetic study of regorafenib in paediatric patients with recurrent or refractory solid malignancies

Eur J Cancer. 2021 Jun 19;153:142-152. doi: 10.1016/j.ejca.2021.05.023. Online ahead of print.

ABSTRACT

BACKGROUND: This phase 1 study evaluated safety, pharmacokinetics (PK), maximum tolerated dose (MTD), and antitumour activity of regorafenib in paediatric patients with solid tumours.

PATIENTS AND METHODS: Patients (aged 6 months to <18 years) with recurrent/refractory solid tumours received oral regorafenib once daily for 3 weeks on/1 week off. The starting dose (60 mg/m2) was derived from an adult physiology-based PK model and scaled to children; dose escalation was followed by safety expansion of the MTD cohort. Treatment-emergent adverse events (TEAEs) were evaluated using National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. Regorafenib PK was evaluated using a population PK model.

RESULTS: Forty-one patients (median age 13 years) received regorafenib (four cohorts: 60-93 mg/m2). Five of 23 evaluable patients experienced dose-limiting toxicities (Grade 4 thrombocytopenia, Grade 3 maculopapular rash, pyrexia, hypertension, and exfoliative dermatitis [each n = 1]). The MTD was defined as 82 mg/m2. The most common Grade ≥3 drug-related TEAE was thrombocytopenia (10%). The incidence and severity of hypertension, diarrhoea, fatigue, hypothyroidism, and hand-foot skin reaction were lower than reported in adults. Regorafenib exposure increased with dose, with substantial overlap because of moderate-to-high interpatient variability. One patient with rhabdomyosarcoma experienced an unconfirmed partial response; 15 patients had stable disease, five for >16 weeks.

CONCLUSIONS: The recommended phase 2 dose of single-agent regorafenib in paediatric patients with solid malignancies is 82 mg/m2. Regorafenib demonstrated acceptable tolerability and preliminary antitumour activity, supporting further investigation in paediatric patients.

CLINICAL TRIAL NUMBER: NCT02085148.

PMID:34157616 | DOI:10.1016/j.ejca.2021.05.023