Single voxel autocorrelation uncovers gradients of temporal dynamics in the hippocampus and entorhinal cortex during rest and navigation.

During navigation, information at multiple scales needs to be integrated. Single-unit recordings in rodents suggest that gradients of temporal dynamics in the hippocampus and entorhinal cortex support this integration. In humans, gradients of representation are observed, such that granularity of information represented increases along the long axis of the hippocampus. The neural underpinnings of this gradient in humans, however, are still unknown. Current research is limited by coarse fMRI analysis techniques that obscure the activity of individual voxels, preventing investigation of how moment-to-moment changes in brain signal are organized and how they are related to behavior. Here, we measured the signal stability of single voxels over time to uncover previously unappreciated gradients of temporal dynamics in the hippocampus and entorhinal cortex. Using our novel, single voxel autocorrelation technique, we show a medial-lateral hippocampal gradient, as well as a continuous autocorrelation gradient along the anterolateral-posteromedial entorhinal extent. Importantly, we show that autocorrelation in the anterior-medial hippocampus was modulated by navigational difficulty, providing the first evidence that changes in signal stability in single voxels are relevant for behavior. This work opens the door for future research on how temporal gradients within these structures support the integration of information for goal-directed behavior.

Transcranial magnetic stimulation to the angular gyrus modulates the temporal dynamics of the hippocampus and entorhinal cortex.

Transcranial magnetic stimulation (TMS) delivered to the angular gyrus (AG) affects hippocampal function and associated behaviors (Thakral PP, Madore KP, Kalinowski SE, Schacter DL. Modulation of hippocampal brain networks produces changes in episodic simulation and divergent thinking. 2020a. Proc Natl Acad Sci U S A. 117:12729-12740). Here, we examine if functional magnetic resonance imaging (fMRI)-guided TMS disrupts the gradient organization of temporal signal properties, known as the temporal organization, in the hippocampus (HPC) and entorhinal cortex (ERC). For each of 2 TMS sessions, TMS was applied to either a control site (vertex) or to a left AG target region (N = 18; 14 females). Behavioral measures were then administered, and resting-state scans were acquired. Temporal dynamics were measured by tracking change in the fMRI signal (i) "within" single voxels over time, termed single-voxel autocorrelation and (ii) "between" different voxels over time, termed intervoxel similarity. TMS reduced AG connectivity with the hippocampal target and induced more rapid shifting of activity in single voxels between successive time points, lowering the single-voxel autocorrelation, within the left anteromedial HPC and posteromedial ERC. Intervoxel similarity was only marginally affected by TMS. Our findings suggest that hippocampal-targeted TMS disrupts the functional properties of the target site along the anterior/posterior axis. Further studies should examine the consequences of altering the temporal dynamics of these medial temporal areas to the successful processing of episodic information under task demand.

A systematic review and meta-analysis of the global epidemiology of pediatric traumatic spinal cord injuries.

Despite being relatively rare, pediatric traumatic spinal cord injury (TSCI) is a debilitating event with high morbidity and long-term damage and dependency. This study aims to provide insight on the epidemiological characteristics of pediatric TSCI worldwide. The studies were included if they provided data for the pediatric population with the diagnosis of TSCI. Information sources included PubMed, Embase, Web of Science, and Scopus. All databases were searched from 1990 to April 2023. The quality of included studies was evaluated by Joanna Briggs Institute Critical Appraisal Tools. The results of the meta-analysis were presented as forest plots. PROSPERO Registration code: CRD42020189757. We identified 87 studies from 18 developed and 11 developing countries. Of the 87 studies evaluated, 52 studies were considered medium quality, 27 studies were considered high quality, and 8 studies were considered low quality. In developed countries, the proportion of TSCIs occurring in patients aged 0-15 years was 3% (95% CI: 2.2%; 3.9%), while in developing countries, it was 4.5% (95% CI: 2.8%; 6.4%). In developed countries, the pooled incidence of pediatric TSCI was 4.3/millions of children aged 0-15/year (95% CI: 3.1; 6.0/millions children aged 0-15/year) and boys comprised 67% (95% CI: 63%; 70%) of cases. The most prevalent level of injury was cervical (50% [95% CI: 41%; 58%]). The frequency of SCI Without Obvious Radiological Abnormality (SCIWORA) was 35% (95% CI: 18%; 54%) among children 0-17 years. The most common etiology in developed countries was transport injuries (50% [95% CI: 42%; 57%]), while in developing countries falls were the leading cause (31% [95% CI: 20%; 42%]). The most important limitation of our study was the heterogeneity of studies in reporting age subgroups that hindered us from age-specific analyses.   Conclusion: Our study provided accurate estimates for the epidemiology of pediatric TSCI. We observed a higher proportion of pediatric TSCI cases in developing countries compared to developed countries. Furthermore, we identified distinct epidemiological characteristics of pediatric TSCI when compared to adult cases and variations between developing and developed countries. Recognizing these unique features allows for the implementation of cost-effective preventive strategies aimed at reducing the incidence and burden of TSCI in children. What is Known: • Pediatric Traumatic Spinal Cord Injury (TSCI) can have profound physical and social consequences for affected children, their families, and society as a whole. • Epidemiological insights are vital for they provide the data and understanding needed to the identification of vulnerable populations, aiding in the development of targeted prevention strategies and effective resource allocation. What is New: • The estimated incidence of pediatric TSCI in developed countries is 4.3 cases per million children aged 0-15. The proportion of pediatric TSCI cases in relation to all-age TSCI cases is 3% in developed countries and 4.5% in developing countries. • The etiology of TSCI in pediatric cases differs between developing and developed countries. In developed countries, transport injuries are the most prevalent cause of pediatric TSCI, while falls are the least common cause. Conversely, in developing countries, falls are the leading cause of pediatric TSCI.

Electro-Optic Fourier Transform Chronometry of Pulsed Quantum Light.

The power spectrum of an optical field can be acquired without a spectrally resolving detector by means of Fourier-transform spectrometry, based on measuring the temporal autocorrelation of the optical field. Analogously, we here perform temporal envelope measurements of ultrashort optical pulses without time resolved detection. We introduce the technique of Fourier transform chronometry, where the temporal envelope is acquired by measuring the frequency autocorrelation of the optical field in a linear interferometer. We apply our technique, which is the time-frequency conjugate measurement to Fourier-transform spectrometry, to experimentally measure the pulse envelope of classical and single-photon light pulses.

Epidemiology of Traumatic Spinal Cord Injury in Developing Countries from 2009 to 2020: A Systematic Review and Meta-Analysis.

INTRODUCTION: Traumatic spinal cord injury (TSCI) is a catastrophic event with a considerable health and economic burden on individuals and countries. This study was performed to update an earlier systematic review and meta-analysis of epidemiological properties of TSCI in developing countries published in 2013. METHODS: Various search methods including online searching in database of EMBASE and PubMed, and hand searching were performed (2012 to May 2020). The keywords "Spinal cord injury," "epidemiology," "incidence," and "prevalence" were used. Based on the definition of developing countries by the International Monetary Fund, studies related to developing countries were included. Data selection was according to PRISMA guidelines. The quality of included studies was evaluated by Joanna Briggs Institute Critical Appraisal Tools. Results of meta-analysis were presented as pooled frequency, and forest, funnel, and drapery plots. RESULTS: We identified 47 studies from 23 developing countries. The pooled incidence of TSCI in developing countries was 22.55/million/year (95% CI: 13.52; 37.62/million/year). Males comprised 80.09% (95% CI: 78.29%; 81.83%) of TSCIs, and under 30 years patients were the most affected age group. Two leading etiologies of TSCIs were motor vehicle crashes (43.18% [95% CI: 37.80%; 48.63%]) and falls (34.24% [95% CI: 29.08%; 39.59%], respectively). The difference among the frequency of complete injury (49.47% [95% CI: 43.11%; 55.84%]) and incomplete injury (50.53% [95% CI: 44.16%; 56.89%]) was insignificant. The difference among frequency of tetraplegia (46.25% [95% CI: 37.78%; 54.83%]) and paraplegia (53.75% [95% CI: 45.17%; 62.22%]) was not statistically significant. The most prevalent level of TSCI was cervical injury (43.42% [95% CI: 37.38%; 49.55%]). CONCLUSION: In developing countries, TSCIs are more common in young adults and males. Motor vehicle crashes and falls are the main etiologies. Understanding epidemiological characteristics of TSCIs could lead to implant-appropriate cost-effective preventive strategies to decrease TSCI incidence and burden.

Estimating the burden of diseases attributable to lead exposure in the North Africa and Middle East region, 1990-2019: a systematic analysis for the Global Burden of Disease study 2019.

BACKGROUND: Lead exposure (LE) and its attributable deaths and disability-adjusted life years (DALYs) have declined in the recent decade; however, it remains one of the leading public health concerns, particularly in regions with low socio-demographic index (SDI) such as the North Africa and Middle East (NAME) region. Hence, we aimed to describe the attributable burden of the LE in this region. METHODS: Data on deaths, DALYs, years of life lost (YLLs), and years lived with disability (YLDs) attributable to LE in the NAME region and its 21 countries from 1990 to 2019 were extracted from the Global Burden of Disease (GBD) 2019 study. RESULTS: In 2019, the age-standardized death and DALY rates attributable to LE were 23.4 (95% uncertainty interval: 15.1 to 33.3) and 489.3 (320.5 to 669.6) per 100,000 in the region, respectively, both of which were higher among men than women. The overall age-standardized death and DALY rates showed 27.7% and 36.8% decreases, respectively, between 1990 and 2019. In this period, Bahrain, the United Arab Emirates, and Turkey had the highest decreases in the age-standardized death and DALY rates, while Afghanistan, Egypt, and Yemen had the lowest ones. Countries within high SDI quintile had lower attributable burden to LE compared with the low SDI quintile. Cardiovascular diseases and chronic kidney diseases accounted for the 414.2 (258.6 to 580.6) and 28.7 (17.7 to 41.7) LE attributable DALYs per 100,000 in 2019, respectively. The attributable YLDs was 46.4 (20.7 to 82.1) per 100,000 in 2019, which shows a 25.7% reduction (-30.8 to -22.5%) over 1990-2019. CONCLUSIONS: The overall LE and its attributed burden by cause have decreased in the region from 1990-2019. Nevertheless, the application of cost-effective and long-term programs for decreasing LE and its consequences in NAME is needed.

Controlling for the effect of arterial-CO2 fluctuations in resting-state fMRI: Comparing end-tidal CO2 clamping and retroactive CO2 correction.

The BOLD signal, as the basis of functional MRI, arises from both neuronal and vascular factors, with their respective contributions to resting state-fMRI still unknown. Among the factors contributing to "physiological noise", dynamic arterial CO2 fluctuations constitutes the strongest and the most widespread modulator of the grey-matter rs-fMRI signal. Some important questions are: (1) if we were able to clamp arterial CO2 such that fluctuations are removed, what would happen to rs-fMRI measures? (2) falling short of that, is it possible to retroactively correct for CO2 effects with equivalent outcome? In this study 13 healthy subjects underwent two rs-fMRI acquisitions. During the "clamped" run, end-tidal CO2 (PETCO2) is clamped to the average PETCO2 level of each participant, while during the "free-breathing" run, the PETCO2 level is passively monitored but not controlled. PETCO2 correction was applied to the free-breathing data by convolving PETCO2 with its BOLD response function, and then regressing out the result. We computed the BOLD resting-state fluctuation amplitude (RSFA), as well as seed-independent mean functional connectivity (FC) as the weighted global brain connectivity (wGBC). Furthermore, connectivity between conditions were compared using coupled intrinsic-connectivity distribution (ICD) method. We ensured that PETCO2 clamping did not significantly alter heart-beat and respiratory variation. We found that neither PETCO2 clamping nor correction produced significant change in RSFA and wGBC. In terms of the ICD, PETCO2 clamping and correction both reduced FC strength in the majority of grey matter regions, although the effect of PETCO2 correction is considerably smaller than the effect of PETCO2 clamping. Interestingly, we found the effect of the commonly employed white-mater/cerebrospinal-fluid regression to be similar to that of PETCO2 clamping than global-signal regression. Nonetheless, both methods reduce functional connectivity significantly more than does PETCO2 clamping. Furthermore, while PETCO2 clamping reduced inter-subject variability in FC, PETCO2 correction increased the variability. Overall PETCO2 correction is not the equivalent of PETCO2 clamping, although it shifts FC values towards the same direction as clamping does.

A Two-Step Guided Waves Based Damage Localization Technique Using Optical Fiber Sensors.

Structural health monitoring (SHM) systems help in reducing maintenance cost and avoiding catastrophic failure of the structure. As a result, they have been a focus of research for the past few decades. Ideally, the methods employed should be low cost and able to detect and localize small levels of damage reliably and accurately. This paper describes a guided waves (GW) based two-step technique for damage detection and localization using fiber Bragg grating (FBG) sensors. The FBG sensors offer benefits such as the ability to be embedded and multiplexed as well as being lightweight and insensitive to electric and magnetic fields, and they have long been seen as a promising solution for the GW measurements in structures. Unfortunately, in the conventional wavelength-based interrogation they have very low signal to noise ratio and as a result low sensitivity. Therefore, the FBG sensor is incorporated in the edge filtering configuration. The major challenges in the use of FBG sensors for GW-based detection are their directional sensitivity and passive nature. The passive nature leads to the reduction in the available actuator-sensor (AS) pairs while the directionality makes the signal processing a challenge. The proposed two-step methodology overcomes these shortcomings of FBG sensors. In the first step the amplitude weighted elliptical approach is used to identify the hotspots due to the inadequate number of AS pairs, the elliptical approach is not sufficient for damage localization. Therefore, in order to further localize the damage the edge reflection based ray-tracing approach is implemented in the second step. Through the two step method, the damage is accurately located. The paper provides the proof of concept of the proposed methodology on an aluminum plate with simulated damage. The results indicate, that indeed the two-step methodology allows accurate damage localization and overcomes the possibility of false detections.

Characterizing the modulation of resting-state fMRI metrics by baseline physiology.

The blood-oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) signal is commonly used to assess functional connectivity across brain regions, particularly in the resting state (rs-fMRI). However, the BOLD fMRI signal is not merely a representation of neural activity, but a combination of neural activity and vascular response. These aspects of the BOLD signal are easily influenced by systemic physiology, potentially biasing BOLD-based functional connectivity measurements. In this work, we focus on the following physiological modulators of the BOLD signal: cerebral blood flow (CBF), venous blood oxygenation, and cerebrovascular reactivity (CVR). We use simulations and experiments to examine the relationship between the physiological parameters and rs-fMRI functional connectivity measurements in three resting-state networks: default mode network, somatosensory network and visual network. By using the general linear model, we demonstrate that physiological modulators significantly impact functional connectivity measurements in these regions, but in a manner that depends on the interplay between signal- and noise-driven correlations. Moreover, we find that the physiological effects vary by brain region and depend on the range of physiological conditions probed; the associations are more complex than previously reported. The results confirm that it is important to account for the effect of physiological modulators when comparing resting-state fMRI metrics. We note that such modulatory effects may be amplified by disease conditions, which will warrant future investigations.

Quantitative mapping of cerebrovascular reactivity using resting-state BOLD fMRI: Validation in healthy adults.

In conventional neuroimaging, cerebrovascular reactivity (CVR) is quantified primarily using the blood-oxygenation level-dependent (BOLD) functional MRI (fMRI) signal, specifically, as the BOLD response to intravascular carbon dioxide (CO2) modulations, in units of [%ΔBOLD/mmHg]. While this method has achieved wide appeal and clinical translation, the tolerability of CO2-related tasks amongst patients and the elderly remains a challenge in more routine and large-scale applications. In this work, we propose an improved method to quantify CVR by exploiting intrinsic fluctuations in CO2 and corresponding changes in the resting-state BOLD signal (rs-qCVR). Our rs-qCVR approach requires simultaneous monitoring of PETCO2, cardiac pulsation and respiratory volume. In 16 healthy adults, we compare our quantitative CVR estimation technique to the prospective CO2-targeting based CVR quantification approach (qCVR, the "standard"). We also compare our rs-CVR to non-quantitative alternatives including the resting-state fluctuation amplitude (RSFA), amplitude of low-frequency fluctuation (ALFF) and global-signal regression. When all subjects were pooled, only RSFA and ALFF were significantly associated with qCVR. However, for characterizing regional CVR variations within each subject, only the PETCO2-based rs-qCVR measure is strongly associated with standard qCVR in 100% of the subjects (p≤0.1). In contrast, for the more qualitative CVR measures, significant within-subject association with qCVR was only achieved in 50-70% of the subjects. Our work establishes the feasibility of extracting quantitative CVR maps using rs-fMRI, opening the possibility of mapping functional connectivity and qCVR simultaneously.

The association between cerebrovascular reactivity and resting-state fMRI functional connectivity in healthy adults: The influence of basal carbon dioxide.

Although widely used in resting-state fMRI (fMRI) functional connectivity measurement (fcMRI), the BOLD signal is only an indirect measure of neuronal activity, and is inherently modulated by both neuronal activity and vascular physiology. For instance, cerebrovascular reactivity (CVR) varies widely across individuals irrespective of neuronal function, but the implications for fcMRI are currently unknown. This knowledge gap compromises our ability to correctly interpret fcMRI measurements. In this work, we investigate the relationship between CVR and resting fcMRI measurements in healthy young adults, in both the motor and the executive-control networks. We modulate CVR within each individual by subtly increasing and decreasing resting vascular tension through baseline end-tidal CO2 (PETCO2), and measure fcMRI during these hypercapnic, hypocapnic and normocapnic states. Furthermore, we assess the association between CVR and fcMRI within and across individuals. Within individuals, resting PETCO2 is found to significantly influence both CVR and resting fcMRI values. In addition, we find resting fcMRI to be significantly and positively associated with CVR across the group in both networks. This relationship is potentially mediated by concomitant alterations in BOLD signal fluctuation amplitude. This work clearly demonstrates and quantifies a major vascular modulator of resting fcMRI, one that is also subject and regional dependent. We suggest that individualized correction for CVR effects in fcMRI measurements is essential for fcMRI studies of healthy brains, and can be even more important in studying diseased brains.

Constrained by our connections: white matter's key role in interindividual variability in visual working memory capacity.

Visual working memory (VWM) plays an essential role in many perceptual and higher-order cognitive processes. Despite its reliance on a broad network of brain regions, VWM has a capacity limited to a few objects. This capacity varies substantially across individuals and relates closely to measures of overall cognitive function (Luck and Vogel, 2013). The mechanisms underlying these properties are not completely understood, although the amplitude of neural signal oscillations (Vogel and Machizawa, 2004) and brain activation in specific cortical regions (Todd and Marois, 2004) have been implicated. Variability in VWM performance may also reflect variability in white matter structural properties. However, data based primarily on diffusion tensor imaging approaches remain inconclusive. Here, we investigate the relationship between white matter and VWM capacity in human subjects using an advanced diffusion imaging technique, diffusion kurtosis imaging. Diffusion kurtosis imaging provides several novel quantitative white mater metrics, among them the axonal water fraction (f(axon)), an index of axonal density and caliber. Our results show that 59% of individual variability in VWM capacity may be explained by variations in f(axon) within a widely distributed network of white matter tracts. Increased f(axon) associates with increased VWM capacity. An additional 12% in VWM capacity variance may be explained by diffusion properties of the extra-axonal space. These data demonstrate, for the first time, the key role of white matter in limiting VWM capacity in the healthy adult brain and suggest that white matter may represent an important therapeutic target in disorders of impaired VWM and cognition.

Mapping the end-tidal CO2 response function in the resting-state BOLD fMRI signal: spatial specificity, test-retest reliability and effect of fMRI sampling rate.

The blood oxygenation level dependent (BOLD) signal measures brain function indirectly through physiological processes and hence is susceptible to global physiological changes. Specifically, fluctuations in end-tidal CO2 (PETCO2), in addition to cardiac rate variation (CRV), and respiratory volume per time (RVT) variations, have been known to confound the resting-state fMRI (rs-fMRI) signal. Previous studies addressed the resting-state fMRI response function to CRV and RVT, but no attempt has been made to directly estimate the voxel-wise response function to PETCO2. Moreover, the potential interactions among PETCO2, CRV, and RVT necessitate their simultaneous inclusion in a multi-regression model to estimate the PETCO2 response. In this study, we use such a model to estimate the voxel-wise PETCO2 response functions directly from rs-fMRI data of nine healthy subjects. We also characterized the effect of sampling rate (TR=2seconds vs. 323ms) on the temporal and spatial variability of the PETCO2 response function in addition to that of CRV and RVT. In addition, we assess the test-retest reproducibility of the response functions to PETCO2, CRV and RVT. We found that despite overlaps across their spatial patterns, PETCO2 explains a unique portion of the rs-fMRI signal variance compared to RVT and CRV. We also found the shapes of the estimated responses are very similar between long- and short-TR data, although responses estimated from short-TR data have higher reproducibility.

Comparing cerebrovascular reactivity measured using BOLD and cerebral blood flow MRI: The effect of basal vascular tension on vasodilatory and vasoconstrictive reactivity.

Cerebrovascular reactivity (CVR) is an important metric of cerebrovascular health. While the BOLD fMRI method in conjunction with carbon-dioxide (CO2) based vascular manipulation has been the most commonly used, the BOLD signal is not a direct measure of vascular changes, and the use of arterial-spin labeling (ASL) cerebral blood flow (CBF) imaging is increasingly advocated. Nonetheless, given the differing dependencies of BOLD and CBF on vascular baseline conditions and the diverse CO2 manipulation types currently used in the literature, knowledge of potential biases introduced by each technique is critical for the interpretation of CVR measurements. In this work, we use simultaneous BOLD-CBF acquisitions during both vasodilatory (hypercapnic) and vasoconstrictive (hypocapnic) stimuli to measure CVR. We further imposed different levels of baseline vascular tension by inducing hypercapnic and hypocapnic baselines, separately from normocapnia by 4mmHg. We saw significant and diverse dependencies on vascular stimulus and baseline condition in both BOLD and CBF CVR measurements: (i) BOLD-based CVR is more sensitive to basal vascular tension than CBF-based CVR; (ii) the use of a combination of vasodilatory and vasoconstrictive stimuli maximizes the sensitivity of CBF-based CVR to vascular tension changes; (iii) the BOLD and CBF vascular response delays are both significantly lengthened at predilated baseline. As vascular tension can often be altered by potential pathology, our findings are important considerations when interpreting CVR measurements in health and disease.

Comparing data-driven physiological denoising approaches for resting-state fMRI: implications for the study of aging.

Introduction: Physiological nuisance contributions by cardiac and respiratory signals have a significant impact on resting-state fMRI data quality. As these physiological signals are often not recorded, data-driven denoising methods are commonly used to estimate and remove physiological noise from fMRI data. To investigate the efficacy of these denoising methods, one of the first steps is to accurately capture the cardiac and respiratory signals, which requires acquiring fMRI data with high temporal resolution. Methods: In this study, we used such high-temporal resolution fMRI data to evaluate the effectiveness of several data-driven denoising methods, including global-signal regression (GSR), white matter and cerebrospinal fluid regression (WM-CSF), anatomical (aCompCor) and temporal CompCor (tCompCor), ICA-AROMA. Our analysis focused on the consequence of changes in low-frequency, cardiac and respiratory signal power, as well as age-related differences in terms of functional connectivity (fcMRI). Results: Our results confirm that the ICA-AROMA and GSR removed the most physiological noise but also more low-frequency signals. These methods are also associated with substantially lower age-related fcMRI differences. On the other hand, aCompCor and tCompCor appear to be better at removing high-frequency physiological signals but not low-frequency signal power. These methods are also associated with relatively higher age-related fcMRI differences, whether driven by neuronal signal or residual artifact. These results were reproduced in data downsampled to represent conventional fMRI sampling frequency. Lastly, methods differ in performance depending on the age group. Discussion: While this study cautions direct comparisons of fcMRI results based on different denoising methods in the study of aging, it also enhances the understanding of different denoising methods in broader fcMRI applications.

Patterns of case fatality and hospitalization duration among nearly 1 million hospitalized COVID-19 patients covered by Iran Health Insurance Organization (IHIO) over two years of pandemic: An analysis of associated factors.

BACKGROUND: Different populations and areas of the world experienced diverse COVID-19 hospitalization and mortality rates. Claims data is a systematically recorded source of hospitalized patients' information that could be used to evaluate the disease management course and outcomes. We aimed to investigate the hospitalization and mortality patterns and associated factors in a huge sample of hospitalized patients. METHODS: In this retrospective registry-based study, we utilized claim data from the Iran Health Insurance Organization (IHIO) consisting of approximately one million hospitalized patients across various hospitals in Iran over a 26-month period. All records in the hospitalization dataset with ICD-10 codes U07.1/U07.2 for clinically/laboratory confirmed COVID-19 were included. In this study, a case referred to one instance of a patient being hospitalized. If a patient experienced multiple hospitalizations within 30 days, those were aggregated into a single case. However, if hospitalizations had longer intervals, they were considered independent cases. The primary outcomes of study were general and intensive care unit (ICU) hospitalization periods and case fatality rate (CFR) at the hospital. Besides, various demographic and hospitalization-associated factors were analyzed to derive the associations with study outcomes using accelerated failure time (AFT) and logistic regression models. RESULTS: A total number of 1 113 678 admissions with COVID-19 diagnosis were recorded by IHIO during the study period, defined as 917 198 cases, including 51.9% females and 48.1% males. The 61-70 age group had the highest number of cases for both sexes. Among defined cases, CFR was 10.36% (95% CI: 10.29-10.42). The >80 age group had the highest CFR (26.01% [95% CI: 25.75-26.27]). The median of overall hospitalization and ICU days were 4 (IQR: 3-7) and 5 (IQR: 2-8), respectively. Male patients had a significantly higher risk for mortality both generally (odds ratio (OR) = 1.36 [1.34-1.37]) and among ICU admitted patients (1.12 [1.09-1.12]). Among various insurance funds, Foreign Citizens had the highest risk of death both generally (adjusted OR = 2.06 [1.91-2.22]) and in ICU (aOR = 1.71 [1.51-1.92]). Increasing age groups was a risk of longer hospitalization, and the >80 age group had the highest risk for overall hospitalization period (median ratio = 1.52 [1.51-1.54]) and at ICU (median ratio = 1.17 [1.16-1.18]). Considering Tehran as the reference province, Sistan and Balcuchestan (aOR = 1.4 [1.32-1.48]), Alborz (aOR = 1.28 [1.22-1.35]), and Khorasan Razavi (aOR = 1.24 [1.20-1.28]) were the provinces with the highest risk of mortality in hospitalized patients. CONCLUSION: Hospitalization data unveiled mortality and duration associations with variables, highlighting provincial outcome disparities in Iran. Using enhanced registry systems in conjunction with other studies, empowers policymakers with evidence for optimizing resource allocation and fortifying healthcare system resilience against future health challenges.

The association between anti-diabetic agents and osteoporosis, sarcopenia, and osteosarcopenia among Iranian older adults; Bushehr Elderly Health (BEH) program.

PURPOSE: Various risk factors are mentioned for osteoporosis, sarcopenia, and osteosarcopenia. Our aim is to assess the impacts of anti-diabetic drugs on these disorders. METHODS: To perform this study, the participants' data was extracted from the Bushehr Elderly Health (BEH) program in Iran. Afterward, the data were categorized into three subgroups: osteoporosis, sarcopenia, and osteosarcopenia, based on WHO and European Working Group on Sarcopenia in Older People (EWGSOP-2) working group definitions. Demographic characteristics, anthropometric measures, past medical history, and current medications were recorded. Pearson chi-squared and simple/multiple logistic regression using Python (3.11.4) and R (4.3.1) programming software assessed the association between anti-diabetic agents and these bone disorders. RESULTS: Out of 1995 participants, 820, 848, and 404 had osteoporosis, sarcopenia, or osteosarcopenia, respectively. Among all types of anti-diabetic drugs, a significant protective association between osteoporosis and consumption of second-generation sulfonylureas was found; Adjusted Odd Ratio (AOR) = 0.65 ([95% CI: 0.45-0.94], p-value = 0.023). No associations were found between sarcopenia and consumption of anti-diabetic agents. A significant association was observed between using Meglitinides and the risk of osteosarcopenia; AOR = 4.98 ([95% CI: 1.5-16.55], p-value = 0.009). CONCLUSION: In conclusion, a protective association between consumption of second-generation sulfonylureas and osteoporosis was found. Moreover, a positive association was found between the consumption of meglitinides and osteosarcopenia. However, to support these findings, further studies are recommended.

Experience transforms crossmodal object representations in the anterior temporal lobes.

Combining information from multiple senses is essential to object recognition, core to the ability to learn concepts, make new inferences, and generalize across distinct entities. Yet how the mind combines sensory input into coherent crossmodal representations - the crossmodal binding problem - remains poorly understood. Here, we applied multi-echo fMRI across a 4-day paradigm, in which participants learned three-dimensional crossmodal representations created from well-characterized unimodal visual shape and sound features. Our novel paradigm decoupled the learned crossmodal object representations from their baseline unimodal shapes and sounds, thus allowing us to track the emergence of crossmodal object representations as they were learned by healthy adults. Critically, we found that two anterior temporal lobe structures - temporal pole and perirhinal cortex - differentiated learned from non-learned crossmodal objects, even when controlling for the unimodal features that composed those objects. These results provide evidence for integrated crossmodal object representations in the anterior temporal lobes that were different from the representations for the unimodal features. Furthermore, we found that perirhinal cortex representations were by default biased toward visual shape, but this initial visual bias was attenuated by crossmodal learning. Thus, crossmodal learning transformed perirhinal representations such that they were no longer predominantly grounded in the visual modality, which may be a mechanism by which object concepts gain their abstraction.

Unveiling the lead exposure attributed burden in Iran from 1990 to 2019 through the lens of the Global Burden of Disease study 2019.

This study aimed to investigate the estimated burden attributed to lead exposure (LE), at the national and subnational levels from 1990 to 2019 in Iran. The burden attributed to LE was determined through the estimation of deaths, disability-adjusted life years (DALYs), years of life lost (YLLs) and years lived with disability (YLDs) using the comparative risk assessment method of Global Burden of Disease (GBD) study presenting as age-standardized per 100,000 person year (PY) with 95% uncertainty intervals (95% UI). Furthermore, the burden of each disease were recorded independently. Eventually, the age-standardized YLLs, DALYs, deaths and YLDs rates attributed to LE demonstrated a decrease of 50.7%, 48.9%, 38.0%, and 36.4%, respectively, from 1990 to 2019. The most important causes of LE burden are divided into two acute and chronic categories: acute, mainly causes mental disorders (DALYs rate of 36.0 in 2019), and chronic, results in cardiovascular diseases (CVDs) (DALYs rate of 391.8) and chronic kidney diseases (CKDs) (DALYs rate of 26.6), with CVDs bearing the most significant burden. At the sub-national level, a decrease in burden was evident in most provinces; moreover, low and low-middle SDI provinces born the highest burden. The burden increased mainly by ageing and was higher in males than females. It was concluded that although the overall decrease in the burden; still it is high, especially in low and low-middle SDI provinces, in advanced ages and in males. Among IDID, CKDs and CVDs that are the most important causes of LE-attributed burden in Iran; CVDs bear the highest burden.