Category: Nevin Manimala

Light Sci Appl. 2021 May 25;10(1):106. doi: 10.1038/s41377-021-00539-0.

ABSTRACT

Is it possible that a measurement of a spin component of a spin-1/2 particle yields the value 100? In 1988 Aharonov, Albert and Vaidman argued that upon pre- and postselection of particular spin states, weakening the coupling of a standard measurement procedure ensures this paradoxical result¹. This theoretical prediction, called weak value, was realised in numerous experiments^2-9, but its meaning remains very controversial^10-19, since its “anomalous” nature, i.e., the possibility to exceed the eigenvalue spectrum, as well as its “quantumness” are debated^20-22. We address these questions by presenting the first experiment measuring anomalous weak values with just a single click, without the need for statistical averaging. The measurement uncertainty is significantly smaller than the gap between the measured weak value and the nearest eigenvalue. Beyond clarifying the meaning of weak values, demonstrating their non-statistical, single-particle nature, this result represents a breakthrough in understanding the foundations of quantum measurement, showing unprecedented measurement capability for further applications of weak values to quantum photonics.

PMID:34035219 | DOI:10.1038/s41377-021-00539-0

Nat Commun. 2021 May 25;12(1):3152. doi: 10.1038/s41467-021-22889-4.

ABSTRACT

The analysis of whole-genome sequencing studies is challenging due to the large number of rare variants in noncoding regions and the lack of natural units for testing. We propose a statistical method to detect and localize rare and common risk variants in whole-genome sequencing studies based on a recently developed knockoff framework. It can (1) prioritize causal variants over associations due to linkage disequilibrium thereby improving interpretability; (2) help distinguish the signal due to rare variants from shadow effects of significant common variants nearby; (3) integrate multiple knockoffs for improved power, stability, and reproducibility; and (4) flexibly incorporate state-of-the-art and future association tests to achieve the benefits proposed here. In applications to whole-genome sequencing data from the Alzheimer’s Disease Sequencing Project (ADSP) and COPDGene samples from NHLBI Trans-Omics for Precision Medicine (TOPMed) Program we show that our method compared with conventional association tests can lead to substantially more discoveries.

PMID:34035245 | DOI:10.1038/s41467-021-22889-4

J Neurointerv Surg. 2021 May 25:neurintsurg-2021-017502. doi: 10.1136/neurintsurg-2021-017502. Online ahead of print.

ABSTRACT

BACKGROUND: The effectiveness and safety of endovascular thrombectomy (EVT) for medium vessel occlusions (MeVO) in the anterior intracranial circulation for patients with acute ischemic stroke (AIS) has yet to be definitively established. We compared outcomes in patients undergoing EVT for large vessel occlusion (LVO) versus those with MeVO.

METHODS: This retrospective cohort study, using an intention to treat design, compared the 90-day modified Rankin Scale (mRS) score between 43 patients with MeVO and 199 with LVO in the anterior intracranial circulation. Secondary outcome measures included vessel recanalization using the Thrombolysis in Cerebral Infarction (TICI) score, procedural complications, post-EVT intracranial hemorrhage (ICH), and infarct size.

RESULTS: The rate of good functional outcome (90-day mRS 0-2) was higher in patients with LVO than in those with MeVO (32.9% vs 27%), but this was not statistically significant (p=0.19). The rate of EVT procedural complications was also not significantly different between the groups (p=0.10), nor was the rate of ICH (p=0.30). There was also no significant difference in TICI scores between groups (p=0.12). Infarct size was larger in the LVO group (p<0.01). Multivariate analysis showed older age, not receiving recombinant tissue plasminogen activator (r-tPA), and larger infarct size were independent predictors of poor functional outcome at 90 days.

CONCLUSION: The 90-day mRS and rate of periprocedural complications were not significantly different between patients treated for LVO and those treated for MeVO with EVT. Older age, not receiving r-tPA, and larger infarct size were independent predictors of poor outcome at 90 days.

PMID:34035151 | DOI:10.1136/neurintsurg-2021-017502

Biomed Phys Eng Express. 2020 Oct 1;6(6). doi: 10.1088/2057-1976/abb5ea.

ABSTRACT

We present a method of directly optimizing on deviations in clinical goal values in radiation therapy treatment planning. Using a new mathematical framework in which metrics derived from the dose-volume histogram are regarded as functionals of an auxiliary random variable, we are able to obtain volume-at-dose and dose-at-volume as infinitely differentiable functions of the dose distribution with easily evaluable function values and gradients. Motivated by the connection to risk measures in finance, which is formalized in this framework, we also derive closed-form formulas for mean-tail-dose and demonstrate its capability of reducing extreme dose values in tail distributions. Numerical experiments performed on a prostate and a head-and-neck patient case show that the direct optimization of dose-volume histogram metrics produced marginally better results than or outperformed conventional planning objectives in terms of clinical goal fulfilment, control of low- and high-dose tails of target distributions and general plan quality defined by a pre-specified evaluation measure. The proposed framework eliminates the disconnect between optimization functions and evaluation metrics and may thus reduce the need for repetitive user interaction associated with conventional treatment planning. The method also has the potential of enhancing plan optimization in other settings such as multicriteria optimization and automated treatment planning.

PMID:34035188 | DOI:10.1088/2057-1976/abb5ea

Biomed Phys Eng Express. 2020 Nov 9;6(6). doi: 10.1088/2057-1976/abc634.

ABSTRACT

Hypertension is the condition where the normal blood pressure is high. This situation is manifested by the high pressure of the blood in the vein towards the vessel wall. Hypertension mostly affects the brain, kidneys, eyes, arteries and heart. Therefore, the diagnosis of this common disease is important. It may take days, weeks or even months for diagnosis. Often a device, called a blood pressure holter, is connected to the person for 24 or 48 h and the person’s blood pressure is recorded at certain intervals. Diagnosis can be made by the specialist physician considering these results. In recent years, various physiological measurement techniques have been used to accelerate this time-consuming diagnostic phase and intelligent models have been proposed. One of these techniques is photopletesmography (PPG). In this study, a model for the detection of hypertension disease in individuals was proposed using chirp z-transform and statistical features (total band power, autoregressive model parameters, standard deviation of signal’s derivative and zero crossing rate) of optimal band-pass filtered short-time PPG signals. The proposed method was successfully applied to 657 PPG trials, which each of them had only 2.1 s signal length and achieved a classification accuracy rate of 77.52% on the test data. The results showed that the diagnosis of hypertension can be performed effectively by chirp z-transform and statistical features and support vector machine classifier using optimal frequency range of 1.4-6 Hz.

PMID:34035194 | DOI:10.1088/2057-1976/abc634

BMJ Open. 2021 May 25;11(5):e047230. doi: 10.1136/bmjopen-2020-047230.

ABSTRACT

OBJECTIVES: We performed a cross-sectional analysis of data from the nationwide Korea National Health and Nutrition Examination Survey to evaluate the association between obesity and chronic rhinosinusitis with nasal polyps (CRSwNP) or without nasal polyp (CRSsNP).

DESIGN: Retrospective cross-sectional analysis of health survey data.

SETTING: Voluntary survey of representative South Korean populations.

PARTICIPANTS: In total, 32 384 individuals aged 19 years or older with available data on CRS and obesity were included.

PRIMARY AND SECONDARY OUTCOME MEASURES: Diagnosis of CRSwNP or CRSsNP was performed by trained otolaryngologists through sinus endoscopy and surveys of medical history. General and central obesity was diagnosed using body mass index (BMI) and waist circumference (WC), respectively.

METHODS: A multivariate logistic regression analysis was used to clarify the association between CRSwNP or CRSsNP and obesity according to BMI and WC. Non-obese individuals were recruited as controls.

RESULTS: The prevalence of CRSwNP was higher in the general (OR, 1.438; 95% CI, 1.170 to 1.768; p<0.001) and central (OR, 1.251; 95% CI, 1.031 to 1.520; p=0.033) obesity groups than in the control group. Prevalence of CRSsNP was not correlated with obesity. In a logistic regression analysis, olfactory dysfunction (OR, 1.329; 95% CI, 1.137 to 1.553; p<0.001) and purulent discharge (OR, 1.383; 95% CI, 1.193 to 1.603; p<0.001) showed a higher incidence in the central obesity group than in the control group.

CONCLUSIONS: We demonstrated an association between CRSwNP and general and central obesity. Further investigations on the mechanism underlying this correlation are necessary for an improved understanding of the pathogenesis of CRSwNP.

PMID:34035104 | DOI:10.1136/bmjopen-2020-047230

BMJ Open. 2021 May 25;11(5):e047790. doi: 10.1136/bmjopen-2020-047790.

ABSTRACT

INTRODUCTION: Intubation-related complications are less frequent when intubation is successful on the first attempt. The rate of first attempt success in the emergency department (ED) and intensive care unit (ICU) is typically less than 90%. The bougie, a semirigid introducer that can be placed into the trachea to facilitate a Seldinger-like technique of tracheal intubation and is typically reserved for difficult or failed intubations, might improve first attempt success. Evidence supporting its use, however, is from a single academic ED with frequent bougie use. Validation of these findings is needed before widespread implementation.

METHODS AND ANALYSIS: The BOugie or stylet in patients Undergoing Intubation Emergently trial is a prospective, multicentre, non-blinded randomised trial being conducted in six EDs and six ICUs in the USA. The trial plans to enrol 1106 critically ill adults undergoing orotracheal intubation. Eligible patients are randomised 1:1 for the use of a bougie or use of an endotracheal tube with stylet for the first intubation attempt. The primary outcome is successful intubation on the first attempt. The secondary outcome is severe hypoxaemia, defined as an oxygen saturation less than 80% between induction until 2 min after completion of intubation. Enrolment began on 29 April 2019 and is expected to be completed in 2021.

ETHICS AND DISSEMINATION: The trial protocol was approved with waiver of informed consent by the Central Institutional Review Board at Vanderbilt University Medical Center or the local institutional review board at an enrolling site. The results will be submitted for publication in a peer-reviewed journal and presented at scientific conferences.

TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registry (NCT03928925).

PMID:34035106 | DOI:10.1136/bmjopen-2020-047790

BMJ Open. 2021 May 25;11(5):e045567. doi: 10.1136/bmjopen-2020-045567.

ABSTRACT

OBJECTIVES: A clear understanding of whether increases in longevity are spent in good health is necessary to support ageing, health and care-related policy.

DESIGN: We conducted a systematic review to update and summarise evidence on trends in health expectancies, in Organisation for Economic Co-operation and Development (OECD) high-income countries.

DATA SOURCES: Four electronic databases (MEDLINE, 1946-19 September 2019; Embase 1980-2019 week 38; Scopus 1966-22 September 2019, Health Management Information Consortium, 1979-September 2019), and the UK Office for National Statistics website (November 2019).

ELIGIBILITY CRITERIA: English language studies published from 2016 that reported trends in healthy, active and/or disability-free life expectancy in an OECD high-income country.

DATA EXTRACTION AND SYNTHESIS: Records were screened independently by two researchers. Study quality was assessed using published criteria designed to identify sources of bias in studies reporting trends, and evidence summarised by narrative synthesis.

FINDINGS: Twenty-eight publications from 11 countries were included, covering periods from 6 to 40 years, between 1970 and 2017. In most countries, gains in healthy and disability-free life expectancy do not match the growth in total life expectancy. Exceptions were demonstrated for women in Sweden, where there were greater gains in disability-free years than life expectancy. Gains in healthy and disability-free life expectancy were greater for men than women in most countries except the USA (age 85), Japan (birth), Korea (age 65) and Sweden (age 77).

CONCLUSION: An expansion of disability in later life is evident in a number of high-income countries, with implications for the sustainability of health and care systems. The recent COVID-19 pandemic may also impact health expectancies in the longer term.

PMID:34035101 | DOI:10.1136/bmjopen-2020-045567

BMJ Open. 2021 May 25;11(5):e046879. doi: 10.1136/bmjopen-2020-046879.

ABSTRACT

INTRODUCTION: The diagnosis of mild cognitive impairment (MCI), that is, the transitory phase between normal age-related cognitive decline and dementia, remains a challenging task. It was observed that a multimodal approach (simultaneous analysis of several complementary modalities) can improve the classification accuracy. We will combine three noninvasive measurement modalities: functional near-infrared spectroscopy (fNIRS), electroencephalography and heart rate variability via ECG. Our aim is to explore neurophysiological correlates of cognitive performance and whether our multimodal approach can aid in early identification of individuals with MCI.

METHODS AND ANALYSIS: This study will be a cross-sectional with patients with MCI and healthy controls (HC). The neurophysiological signals will be measured during rest and while performing cognitive tasks: (1) Stroop, (2) N-back and (3) verbal fluency test (VFT). Main aims of statistical analysis are to (1) determine the differences in neurophysiological responses of HC and MCI, (2) investigate relationships between measures of cognitive performance and neurophysiological responses and (3) investigate whether the classification accuracy can be improved by using our multimodal approach. To meet these targets, statistical analysis will include machine learning approaches.This is, to the best of our knowledge, the first study that applies simultaneously these three modalities in MCI and HC. We hypothesise that the multimodal approach improves the classification accuracy between HC and MCI as compared with a unimodal approach. If our hypothesis is verified, this study paves the way for additional research on multimodal approaches for dementia research and fosters the exploration of new biomarkers for an early detection of nonphysiological age-related cognitive decline.

ETHICS AND DISSEMINATION: Ethics approval was obtained from the local Ethics Committee (reference: 83/19). Data will be shared with the scientific community no more than 1 year following completion of study and data assembly.

TRIAL REGISTRATION NUMBER: ClinicalTrials.gov, NCT04427436, registered on 10 June 2020, https://clinicaltrials.gov/ct2/show/study/NCT04427436.

PMID:34035103 | DOI:10.1136/bmjopen-2020-046879

BMJ Open. 2021 May 25;11(5):e042821. doi: 10.1136/bmjopen-2020-042821.

ABSTRACT

AIMS: To evaluate the type 2 diabetes mellitus (T2DM) risk of individuals with different types of dyslipidaemia and compare the predictive value of distinct lipid parameters in predicting T2DM.

METHODS: We conducted a secondary analysis of data from the China Health and Retirement Longitudinal Study (CHARLS). 17 708 individuals over 45 years old were interviewed, and 11 847 blood samples were collected at the baseline survey (2011-2012). Outcome of T2DM was confirmed during two follow-up surveys (2013-2014 and 2015-2016). The HRs and 95% CI of T2DM associated with dyslipidaemia were estimated by Cox proportional hazards regressions model. The discriminatory value of eight lipid parameters were compared by the area under the receiver operating characteristic (ROC) curve (AUC).

RESULTS: A total of 7329 participants were enrolled in our analysis; during the mean follow-up time of 3.4 years, 387 (5.28%) participants developed new-onset diabetes. Compared with participants in normal lipid levels, the T2DM risk of those with hypercholesterolaemia, hypertriglyceridaemia and low high-density lipoprotein cholesterol (HDL-C) were significantly increased (HRs (95% CI) were 1.48 (1.11 to 1.96), 1.92 (1.49 to 2.46) and 1.67 (1.35 to 2.07), respectively). The AUCs of non-HDL-C (0.685, 95% CI 0.659 to 0.711), triglyceride (TG) (0.684, 95% CI 0.658 to 0.710), total cholesterol (TC)/HDL-C (0.685, 95% CI 0.659 to 0.712) and TG/HDL-C (0.680, 95% CI 0.654 to 0.706) were significantly (p<0.005) larger than that of other lipid parameters.

CONCLUSION: Middle-aged and elderly adults with hypertriglyceridaemia, hypercholesterolaemia and low HDL-C were at higher risk for developing diabetes. Non-HDL-C, TG, TC/HDL and TG/HDL have greater performance than other lipid parameters in predicting T2DM incidence.

PMID:34035089 | DOI:10.1136/bmjopen-2020-042821