Tag: nevin manimala

Opt Lett. 2021 Sep 1;46(17):4390-4393. doi: 10.1364/OL.435812.

ABSTRACT

The simulation of statistically accurate time-integrated dynamic speckle patterns using a physics-based model that accounts for spatially varying sample properties is yet to be presented in biomedical optics. In this Letter, we propose a solution to this important problem based on the Karhunen-Loève expansion of the electric field and apply our method to the formalisms of both laser speckle contrast imaging and diffuse correlation spectroscopy. We validate our technique against solutions for speckle contrast for different forms of homogeneous field and also show that our method can readily be extended to cases with spatially varying sample properties.

PMID:34470023 | DOI:10.1364/OL.435812

Opt Lett. 2021 Sep 1;46(17):4426-4429. doi: 10.1364/OL.437740.

ABSTRACT

In this Letter, we propose a real-time machine learning scheme of a tracking optical intensity-modulation and direct-detection (IMDD) system’s conditional distribution using linear optical sampling and inline Gaussian mixer modeling (GMM) programming. End-to-end conditional distribution tracking enables an adaptive decoding of optical IMDD signals, with robustness to the bias point shift of the optical intensity modulator. Experimental demonstration is conducted over a 20-Gbits/s optical pulse amplitude modulation-4 (PAM-4) modulation system. Optical PAM-4 signals are optically down-sampled by short pulses to 250 Msa/s. Then, statistical characters of signal distribution can be estimated using inline GMM processing. Due to the real-time learned distribution, intelligent decoding of received signals exhibits a perfect adaptation to the changing bias point of a Mach-Zendner intensity modulator, enhancing the communication reliability with bit error rate (BER) below 3.8⋅10^-3. In addition, the proposed scheme also provides the possibility of practical implementation to other machine learning signal decoding methods.

PMID:34470032 | DOI:10.1364/OL.437740

Opt Lett. 2021 Sep 1;46(17):4132-4135. doi: 10.1364/OL.431350.

ABSTRACT

The airborne measurement of a temperature profile from 10.5 km down towards ground (≈1.4km above sea level) during daytime by means of a lidar utilizing Rayleigh-Brillouin (RB) scattering is demonstrated for the first time, to our knowledge. The spectra of the scattered light were measured by tuning the laser (λ=354.9nm) over a 11 GHz frequency range with a step size of 250 MHz while using a Fabry-Perot interferometer as a spectral filter. The measurement took 14 min and was conducted over a remote area in Iceland with the ALADIN Airborne Demonstrator on-board the DLR Falcon aircraft. The temperature profile was derived by applying an analytical RB line shape model to the backscatter spectra, which were measured at different altitudes with a vertical resolution of 630 m. A comparison with temperature profiles from radiosonde observations and model temperatures shows reasonable agreement with biases of less than ±2K. Based on Poisson statistics, the random error of the derived temperatures is estimated to vary between 0.1 K and 0.4 K. The work provides insight into the possible realization of airborne lidar temperature profilers based on RB scattering.

PMID:34469957 | DOI:10.1364/OL.431350

Opt Lett. 2021 Sep 1;46(17):4386-4389. doi: 10.1364/OL.435799.

ABSTRACT

Nitrogen-vacancy color centers (NVs) in diamond have several potential applications ranging from quantum computing to data storage. However, artificial NVs are often close to the surface, which limits their spatial density and applicability. Here we demonstrate an effective and precise method for preparing deep single NVs in diamond. The method is based on a spatial-shaped femtosecond laser to overcome laser defocus in high-refractive materials, and realizes the preparation of single NVs at 95 µm. In addition, owing to the good energy distribution of the shaped laser focus, the single NVs exhibit a statistic yield of 56%±11% with excellent qualities. This processing method will contribute to the integration of color centers with emerging optical elements and high-density data storage.

PMID:34470022 | DOI:10.1364/OL.435799

J Healthc Qual. 2021 Aug 31. doi: 10.1097/JHQ.0000000000000322. Online ahead of print.

ABSTRACT

BACKGROUND: Opioid-induced respiratory depression (OIRD) is a serious complication that can lead to negative outcomes. There are known risk factors for OIRD; however, a lack of national guidelines for the prevention and early detection of OIRD exists.

METHODS: An evidence-based practice study was conducted to create an enhanced monitoring (EM) program. The EM program consisted of risk stratification of surgical spine patients, including the use of STOP-BANG screening for obstructive sleep apnea, capnography monitoring, use of home positive airway pressure therapy, capnography alarm optimization, hospitalist consultation, nursing education, and patient education.

RESULTS: Approximately 17% (N = 937/5,462) of surgical spine patients were enrolled in the EM program. Fifty-six percent of EM patients were monitored with capnography and had out of range end-tidal carbon dioxide levels 17% of the time. The rate of transfers to the intensive care unit (ICU) for OIRD decreased, though not statistically significant (p = .151).

CONCLUSIONS: The EM program with risk stratification was found to reduce transfers to the ICU for OIRD. Although not statistically significant, the decreased number of transfers was clinically significant. Engagement of the interprofessional team and capnography alarm parameter optimization helped to reduce nonactionable alarms.

PMID:34469926 | DOI:10.1097/JHQ.0000000000000322

Menopause. 2021 Aug 30. doi: 10.1097/GME.0000000000001847. Online ahead of print.

ABSTRACT

OBJECTIVE: This study explored the clinical management practices of healthcare providers who treat menopausal women in an urban Mid-South area. The study specifically examined their knowledge of prescribing and counseling related to the care of women who present with complaints or clinical findings of genitourinary syndrome of menopause.

METHODS: An electronic questionnaire was distributed to healthcare providers involved in the care of women undergoing menopausal transition spanning a variety of medical specialties. The questionnaire was distributed to academic program directors, coordinators, and ListServ administrators to forward to targeted respondents. Items included demographic questions, clinical knowledge, management practices, and preferences. Statistical analysis for associations between demographics was performed using Chi-squared tests and between age groups with Kruskal Wallis tests.

RESULTS: The final sample contained 106 healthcare providers. Respondents were demographically diverse and encompassed multiple levels of professional training including Attendings, Trainees (Residents and Fellows), as well as Advanced Practice Registered Nurses. Significant differences were noted in many areas examined in our questionnaire, comprising knowledge, management, counseling, and prescribing practices surrounding the treatment of genitourinary syndrome of menopause when accounting for training level, specialty, and years in practice. Among all respondents, 10.4% reported rarely or never discussing menopausal symptoms with their patients. Most respondents (76.4%) stated they had prescribed topical therapies for genitourinary syndrome of menopause, with over 90% of practitioners prescribing lubricants/moisturizers and estradiol cream; however, only 55% reported being familiar with the US Food and Drug Administration’s boxed warning on low-dose vaginal estrogen. Nearly half of the respondents (49%) reported being uncomfortable counseling about the boxed warning on low-dose vaginal estrogen.

CONCLUSION: This study identifies gaps in Mid-South healthcare providers’ awareness of the boxed warning on low-dose vaginal estrogen as well as their comfort level in providing counseling regarding the risks, benefits, and alternatives to vaginal estrogen. Integrated practice between physicians and Advanced Practice Registered Nurses can lead to a significant benefit to patients experiencing menopause as shared experience and knowledge are shared between each group. Our survey does reveal gaps in knowledge and practice for optimal outcomes for patients experiencing genitourinary syndrome of menopause. These results will be useful in providing continuing education to providers and more effective communication, evaluation, and treatment to patients.

PMID:34469937 | DOI:10.1097/GME.0000000000001847

Phys Med Biol. 2021 Sep 1. doi: 10.1088/1361-6560/ac22dc. Online ahead of print.

ABSTRACT

Brain-shift during neurosurgery compromises the accuracy of tracking the boundaries of the tumor to be resected. Although several studies have used various finite element models (FEMs) to predict inward brain-shift, evaluation of their accuracy and efficiency based on public benchmark data has been limited. This study evaluates several FEMs proposed in the literature (various boundary conditions, mesh sizes, and material properties) by using intraoperative imaging data (the public REtroSpective Evaluation of Cerebral Tumors [RESECT] database). Four patients with low-grade gliomas were identified as having inward brain-shifts. We computed the accuracy (using target registration error) of several FEM-based brain-shift predictions and compared our findings. Since information on head orientation during craniotomy is not included in this database, we tested various plausible angles of head rotation. We analyzed the effects of brain tissue viscoelastic properties, mesh size, craniotomy position, cerebrospinal fluid drainage level, and rigidity of meninges and then quantitatively evaluated the trade-off between accuracy and central processing unit time in predicting inward brain-shift across all models with second-order tetrahedral FEMs. The mean initial Target Registration Error (TRE) was 5.78±3.78 mm with rigid registration. FEM prediction (edge-length, 5 mm) with non-rigid meninges led to a mean TRE correction of 1.84±0.83 mm assuming heterogeneous material. Results show that, for the low-grade glioma patients in the study, including non-rigid modeling of the meninges was significant statistically. In contrast including heterogeneity was not significant. To estimate the optimal head orientation and CSF drainage, an angle step of 5° and an CSF height step of 5 mm were enough leading to <0.26mm TRE fluctuation.

PMID:34469879 | DOI:10.1088/1361-6560/ac22dc

Am J Ther. 2021 Aug 19. doi: 10.1097/MJT.0000000000001422. Online ahead of print.

ABSTRACT

BACKGROUND: This study aims to compare the poisoned patients who could not be administered activated charcoal because of its unavailability with the poisoned patients who were administered charcoal in the later period and to reveal the results about its effectiveness.

STUDY QUESTION: Is the use of activated charcoal effective against poisoning caused by oral medication?

STUDY DESIGN: This retrospective cohort study with historical control was planned at a tertiary hospital. Patients older than 18 years were admitted to the emergency department because of oral drug poisoning during the study periods. A total of 1159 patients who were not given activated charcoal and 877 patients who were given activated charcoal were included in this study.

MEASURES AND OUTCOMES: The frequency of clinical findings secondary to the drug taken, the frequency of antidote use, the frequency of intubation, and the hospitalization length were determined as clinical outcome parameters.

RESULTS: There was no statistically significant difference in the development of central nervous system findings, cardiovascular system findings, frequency of intubation, and blood gas disorders, as well as the length of hospitalization periods according to the activated charcoal application. Hepatobiliary system findings and electrolyte disturbances were found to be less common in patients given activated charcoal. The frequency of tachycardia, speech impairment, coma, and respiratory acidosis was found to be statistically higher in patients who were administered activated charcoal. The hospitalization period of the patients who were given activated charcoal was longer in patients with drug findings; however, there was no difference in the hospitalization periods of the patients who were given an antidote.

CONCLUSIONS: The use of activated charcoal in poisoned patients may not provide sufficient clinical benefits. However, clinical studies with strong evidence levels are needed to determine activated charcoal’s clinical efficacy, which is still used as a universal antidote.

PMID:34469920 | DOI:10.1097/MJT.0000000000001422

Neuroimage. 2021 Aug 29;243:118518. doi: 10.1016/j.neuroimage.2021.118518. Online ahead of print.

ABSTRACT

Null models are useful for assessing whether a dataset exhibits a non-trivial property of interest. These models have recently gained interest in the neuroimaging community as means to explore dynamic properties of functional Magnetic Resonance Imaging (fMRI) time series. Interpretation of null-model testing in this context may not be straightforward because (i) null hypotheses associated to different null models are sometimes unclear and (ii) fMRI metrics might be ‘trivial’, i.e. preserved under the null hypothesis, and still be useful in neuroimaging applications. In this commentary, we review several commonly used null models of fMRI time series and discuss the interpretation of the corresponding tests. We argue that, while null-model testing allows for a better characterization of the statistical properties of fMRI time series and associated metrics, it should not be considered as a mandatory validation step to assess their relevance in representing brain functional dynamics.

PMID:34469853 | DOI:10.1016/j.neuroimage.2021.118518

J Affect Disord. 2021 Aug 24;295:183-191. doi: 10.1016/j.jad.2021.08.025. Online ahead of print.

ABSTRACT

BACKGROUND: Rhythms And You (RAY) is an online intervention for bipolar disorders (BD) based on Interpersonal and Social Rhythm Therapy. We examined RAY’s feasibility and acceptability for individuals with BD recruited from primary care. Because online interventions may be more effective when paired with human support, we evaluated RAY with and without weekly brief (∼5 min) calls from clinical helpers (CH).

METHODS: Participants (n = 47) meeting criteria for BD I, II or other specified BD, presenting for primary care, were randomly assigned to RAY, RAY-CH, or Adjunctive Reading Material (ARM) control. RAY consisted of 12 weekly online modules. ARM consisted of 12 weekly emails. Participants were assessed at baseline, 4, 8, and 12 weeks.

RESULTS: RAY showed high completion rates and Client Satisfaction Questionnaire scores (36/47, 77% and 25.1 ± 5.5, respectively; no group differences). Effect sizes for RAY- CH ranged from small [Internal State Scale-Activation Subscale (ISS-ACT); d = 0.3] to large [SF-12 Mental Health Composite Score (SF-12 MHC); d = 1.3]. ARM also showed moderate effects (ISS-ACT d = 0.7; Quick Inventory of Depressive Symptoms, d = 0.8). SF-12 MHC scores showed a time*group interaction (F = 2.38, df = 6,32, p = 0.05) favoring RAY-CH. Number of logins trended toward significant association with improved social rhythm regularity (F = 4.09, df = 1, 17, p = 0.06).

LIMITATIONS: Sample size is small, limiting conclusions that can be drawn.

CONCLUSIONS: Remote delivery of RAY for individuals with BD is feasible and acceptable. More time spent engaged in RAY was associated with greater improvement in social rhythm regularity. Preliminary evidence suggests adding brief human support to RAY may yield better outcomes.

PMID:34469857 | DOI:10.1016/j.jad.2021.08.025