T1 Data Research Articles

The effectiveness of mindfulness-based interventions in treating mental health and addiction: a cross-sectional study

Objective: This study aimed to provide a snapshot of the current landscape, drawing upon existing research to evaluate the extent to which online mindfulness-based interventions (MBIs) have been integrated into mainstream treatment paradigms and their observed outcomes. Methods: The initial month of the full mindfulness virtual community (F-MVC) intervention included 12 video modules focusing on students' known stressors and mindfulness exercises; private online forums for peer discussions; and 20-minute live video conferences led by professionals in anonymous groups. During the next four weeks of F-MVC, participants were limited to watching modules in video format. The online surveys were conducted at T1, T2, and T3 - 4 weeks and 8 weeks, respectively. Results: Out of the 113 students who gave T1 data, there were 28 male and 85 female students, with an average age of 24.8 years. At the T3 follow-up, after making adjustments for comparison purposes, there were notable decreases in depression scores for F-MVC (change in score of -4.03; P

Emergence of Entrepreneurs by Facing Financial Distress: The Mediating Mechanism of Entrepreneurial Motivation

The purpose of this research study is to examine the phenomena that led to rise in entrepreneurs post COVID-19 pandemic, Inflation and unemployment; how financial distress in Pakistan lead to entrepreneurial motivation, and to advance the study in domain of motivation that makes someone opt for entrepreneurship. The results of the study provide a means to understand how financial distress is linked with entrepreneurial behavior to startup ventures. The study also entails how entrepreneurial motivation turns into entrepreneurial behavior in presence of boundary condition of financial self-efficacy. The research study has different theoretical, practical and economic implications as well. The theory of entrepreneurship embeds the study model explaining the casual relations of the variables. Data sample has been collected from 200 entrepreneurs at three points of times. At T1 data was gathered for financial distress, at T2 data was gathered for entrepreneurial motivation and at T3 data was gathered for financial self-efficacy, entrepreneurial intentions and entrepreneurial behavior. Results of hypothesis test shows that financial distress has positive impact on Entrepreneurial intention and has not impacted Entrepreneurial behavior positively, Entrepreneurial motivation positively impacted Intention and behavior. Therefore, the study provides important insights into unexplored drivers of financial distress towards entrepreneurial motivation and intention and behavior contributing existing literature pertaining to entrepreneurial motivation. The study has uncovered fruitful aspects of entrepreneurship for future study.

The alteration of cortical microstructure similarity in drug-resistant epilepsy correlated with mTOR pathway genes

Drug-resistant epilepsy (DRE) is associated with distributed laminar disruptions due to cytoarchitectonic pathologies, which may be characterized by multimodal MRI approaches such as morphometric similarity networks (MSNs). However, the genetic and histological underpinning of MSN alterations in DRE remains poorly understood, hampering its clinical application. We enrolled 60 patients with DRE and 23 controls, acquiring T1 and diffusion spectrum imaging data with a 3.0T GE SIGNA Premier scanner. Morphometric similarity networks (MSNs) were constructed and analyzed to identify microstructure similarity differences between patients and controls. Subsequently, patient-specific MSN alteration patterns were associated with gene expression using the GAMBA tool, and layer-specific neuronal signature mapping were also applied. During these analyses, sex and age were adjusted as covariates and multiple comparisons corrections were applied when appropriate. We observed widespread MSN changes in patients with DRE and identified five distinct MSN alteration patterns. Major patterns presented pattern-specific associations with expressions of epilepsy-related genes, particularly involving the mTOR pathway. Histological analysis confirmed the presence of cortical microstructure changes in areas with MSN alterations and revealed cellular abnormalities matching the aforementioned genetic risks. Our findings highlight the potential of quantifying laminar-related microstructure integrity using MSN to uncover the cytoarchitectonic changes in the pathophysiology of DRE. This approach may facilitate the identification of genetic and histological underpinnings of MSN alterations in DRE, ultimately aiding in the development of targeted therapeutic strategies. The National Natural Science Foundation of China, the Ministry of Science and Technology of the People's Republic of China, and the Beijing Municipal Health Commission.

NMR Self-Diffusion and Transverse Relaxation Time in Bitumen: The Effect of Aging.

In this investigation the dynamics of two types of bitumens with different penetration grade were tested by using dynamic shear rheometry (DSR) and Nuclear Magnetic Resonance (NMR) at unaged conditions, and upon both short- and long-term artificial aging. The gel-sol transition temperature was found to increase with increasing the time of aging treatment. Arrhenius parameters of the viscosity were found, unexpectedly, to be correlated with those of simple liquids, suggesting that the two kinds of systems, although chemically and physically quite different, share the same basic process at the molecular level. The molecular dynamics has been then investigated by NMR Pulsed Field Gradient Stimulated-Echo (PFGSE) and relaxometry (Carr-Purcell-Meiboom-Gill, CPMG, spin-echo pulse sequence) to capture the effect of aging upon dynamics variables such as self-diffusion coefficients D and transverse relaxation times T2 . The translational diffusion at T> of the light molecular components of both types of bitumens was characterized by broad distributions of D which were found independent of the experimental time scale up to 0.2 s. Similarly, T2 data could be described as a continuous unimodal distributions of relaxation times determined both at T< and T> .

Environment profiles, social participation patterns, depressive symptoms and quality of life of disabled older adults: a longitudinal investigation

Objectives This study used the World Health Organization’s healthy ageing framework to explore longitudinal influences of environment profiles and social participation (SP) patterns on depressive symptoms (DSs) and on quality of life (QOL). Methods Data were collected from a sample of community-dwelling older adults in Taiwan in 2018 (T1; N = 1,314) and a follow-up survey in 2020 (T2; N = 831). Latent class analysis was conducted to obtain environment and SP profiles. Multilevel modeling was carried out to explicate the hypothesized associations. Results Three unique environment profiles, labeled as Highly- (Highly-FE), Moderately- (Moderately-FE) and Weakly-Facilitative Environment (Weakly-FE), were identified from T1 data. The three SP classes that were obtained from T1 and T2 data denoted High-, Moderate- and Low-SP. Participants in the ‘Highly-FE’ class were more likely to belong to the ‘High-SP’ and ‘Moderate-SP’ subgroups and exhibited significantly fewer DSs and better QOL. The associations were confirmed both cross-sectionally and longitudinally. Conclusion Interventions should be developed to promote or maintain preferred SP to maximize the current and future mental health and subjective well-being of disabled older adults.

Experimental and simulation study on the estimation of surface relaxivity of clay minerals

Nuclear Magnetic Resonance (NMR) is an important tool for the evaluation of pore structure and petrophysical properties of reservoir rocks. Pore Surface relaxivity (ρ2), which controls the relaxation decay due to the interaction between the spins and the pore surface, is an important parameter that impacts the interpretation of NMR for petrophysical properties. Sandstone rocks have complex minerology and consist of different clay minerals. Earlier efforts have reported the surface relaxivity of different rock types such as sandstone or carbonate, but less attention was given to the estimation of individual clay minerals surface relaxivity. The surface complexity and variable mineralogy (especially paramagnetic and ferromagnetic minerals) of clays can both impact the surface relaxivity and relaxation times in clays and porous media containing clays. This study, using for the first time both simulation and experimental approaches, aims to systematically investigate the surface relaxivity of clays characterized by variable mineralogy and iron content. A glass beads sample (iron free) and 5 different pure clay minerals samples (ranked by increasing iron content: Kaolinite, Smectite, Illite, Chlorite, and Nontronite) were prepared with similar average grain sizes (500 μm). The determination of surface relaxivity requires prior measurement of pore surface-to-volume ratio (S/V) using an independent method in addition to obtaining T2 relaxation time. Two methods, among the most widely used, were used here for S/V determination including BET N2 gas adsorption and 3D micro CT imaging. The 3D images were also used to conduct NMR simulations to reproduce the experimental data. The estimated surface relaxivity values from both methods were compared and correlated to the iron content of the different clays. The surface relaxivity values obtained based on BET-derived S/V showed reasonable values (29–343 μm/s) that have a strong positive relationship with iron content of the clays. The documented equation relating surface relaxivity and iron content can be potentially utilized to predict surface relaxivity based on the compositional analysis of clays. On the other hand, digital images did not capture the surface complexity of clays thus significantly underestimated S/V which consequently resulted in overestimated surface relaxivity (898–11000 μm/s) that were physically non-feasible. Supporting the same argument, the simulated T2 relaxation distribution showed significant mismatch with the experimental data for the clay samples while an excellent match was observed for the glass beads sample. This can be attributed to the smooth surface of the glass beads, unlike the complex clays. The reported surface relaxivity values (based on BET-derived S/V) for the individual clay minerals can be used to perform NMR simulation and interpretation studies conducted on sandstone or shale formations. Careful attention should be given when performing NMR simulation on micro-CT digital images of samples containing clay due to the inadequacy of such images in capturing the complex surface and microporous nature of clays. The outcomes from this study can improve the interpretation of NMR T2 data and the determination of NMR-derived pore size distribution and petrophysical properties. The reported surface relaxivity values for clay can also inform the NMR simulation.

In Vivo Myelin Water Quantification Using Diffusion–Relaxation Correlation MRI: A Comparison of 1D and 2D Methods

Multidimensional Magnetic Resonance Imaging (MRI) is a versatile tool for microstructure mapping. We use a diffusion weighted inversion recovery spin echo (DW-IR-SE) sequence with spiral readouts at ultra-strong gradients to acquire a rich diffusion–relaxation data set with sensitivity to myelin water. We reconstruct 1D and 2D spectra with a two-step convex optimization approach and investigate a variety of multidimensional MRI methods, including 1D multi-component relaxometry, 1D multi-component diffusometry, 2D relaxation correlation imaging, and 2D diffusion-relaxation correlation spectroscopic imaging (DR-CSI), in terms of their potential to quantify tissue microstructure, including the myelin water fraction (MWF). We observe a distinct spectral peak that we attribute to myelin water in multi-component T1 relaxometry, T1-T2 correlation, T1-D correlation, and T2-D correlation imaging. Due to lower achievable echo times compared to diffusometry, MWF maps from relaxometry have higher quality. Whilst 1D multi-component T1 data allows much faster myelin mapping, 2D approaches could offer unique insights into tissue microstructure and especially myelin diffusion.

Potential clinical feasibility of synthetic MRI in bladder tumors: a comparative study with conventional MRI.

Synthetic magnetic resonance imaging (MRI) can provide quantitative information about inherent tissue properties and synthesize tailored contrast-weighted images simultaneously in a single scan. This study aimed to investigate the clinical feasibility of synthetic MRI in bladder tumors. A total of 47 patients (37 males; mean age: 66±10 years old) with postoperative pathology-confirmed papillary urothelial neoplasms of the bladder were enrolled in this retrospective study. A 2-dimensional (2D) multi-dynamic multi-echo pulse sequence was performed for synthetic MRI at 3T. The overall image quality, lesion conspicuity, contrast resolution, resolution of subtle anatomic structures, motion artifact, blurring, and graininess of images were subjectively evaluated by 2 radiologists independently using a 5-point Likert scale for qualitative analysis. The signal intensity ratio (SIR), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were measured for quantitative analysis. Linear weighted Kappa, Wilcoxon's signed-rank test, and the Mann-Whitney U-test were used for statistical analysis. The interobserver consistency was excellent (κ values: 0.607-1). Synthetic T1-weighted (syn-T1w) and synthetic T2-weighted (syn-T2w) images obtained scores of 4 in most subjective terms, which were relatively smaller than those of conventional images. The SIR and SNR of syn-T1w were significantly higher than those of con-T1w images (SIR 2.37±0.86 vs. 1.47±0.20, P<0.001; SNR 21.83±9.43 vs. 14.81±3.30, P<0.001). No difference was found in SIR between syn-T2w and conventional T2-weighted (con-T2w) images, whereas the SNR of the syn-T2w was significantly lower (8.79±4.06 vs. 26.49±6.80, P<0.001). Additionally, the CNR of synthetic images was significantly lower than that of conventional images (T1w 1.41±0.72 vs. 2.68±1.04; T2w 1.40±0.87 vs. 4.03±1.55, all P<0.001). Synthetic MRI generates morphologic magnetic resonance (MR) images with diagnostically acceptable image quality in bladder tumors, especially T1-weighted images with high image contrast of tumors relative to urine. Further technological improvements are needed for synthetic MRI to reduce noise. Combined with T1, T2, and proton density (PD) quantitative data, synthetic MRI has potential for clinical application in bladder tumors.

Iconicity in the emergence of a phonological system?

AbstractIconicity has been described as an impetus for creating sign forms in emerging sign languages and forming signs in established sign languages. Iconic signs are defined as spontaneous or stable signs that directly reflect the representation of their referent. In established sign languages, iconic signs have phonological features. Regarding the link between the motivation for iconic signs and phonological features, we aim to investigate how iconicity might influence the emergence of a phonological system along with the evolution of a new sign language by observing how the rise of a phonological system might be revealed by the evolution of emerging iconic gestures and signs in a new sign language. For this purpose, we inventoried and coded the iconicity nature and phonological structure of 200 signed lexical items collected in two moments of Sao Tome and Principe Sign Language (LGSTP) emergence: at T1 (after 2 years since the deaf habitants initiated their social meetings) and T2 (8 years subsequent to T1 data collection). In the 8 years of LGSTP’s emergence, we found a dominance of iconic signs in tandem with changes in the signs’ internal structure. The handshape is revealed to be the phonological parameter with the greatest development, presenting itself as more complex. The LGSTP lexicon reveals that iconicity seems to prompt the emergence of sign forms. However, iconic strategies remain stable across the evolution of the emergent signs and are independent of the internal structure change of the sign.

Multi-scale structural alterations of the thalamus and basal ganglia in focal epilepsy using 7T MRI.

Focal epilepsy is characterized by repeated spontaneous seizures that originate from cortical epileptogenic zone networks (EZN). Analysis of intracerebral recordings showed that subcortical structures, and in particular the thalamus, play an important role in seizure dynamics as well, supporting their structural alterations reported in the neuroimaging literature. Nonetheless, between-patient differences in EZN localization (e.g., temporal vs. non-temporal lobe epilepsy) as well as extension (i.e., number of epileptogenic regions) might impact the magnitude as well as spatial distribution of subcortical structural changes. Here we used 7 Tesla MRI T1 data to provide an unprecedented description of subcortical morphological (volume, tissue deformation, and shape) and longitudinal relaxation (T1 ) changes in focal epilepsy patients and evaluate the impact of the EZN and other patient-specific clinical features. Our results showed variable levels of atrophy across thalamic nuclei that appeared most prominent in the temporal lobe epilepsy group and the side ipsilateral to the EZN, while shortening of T1 was especially observed for the lateral thalamus. Multivariate analyses across thalamic nuclei and basal ganglia showed that volume acted as the dominant discriminator between patients and controls, while (posterolateral) thalamic T1 measures looked promising to further differentiate patients based on EZN localization. In particular, the observed differences in T1 changes between thalamic nuclei indicated differential involvement based on EZN localization. Finally, EZN extension was found to best explain the observed variability between patients. To conclude, this work revealed multi-scale subcortical alterations in focal epilepsy as well as their dependence on several clinical characteristics.

The influence of minority stress-related experiences on mental wellbeing for trans/gender-diverse and cisgender youth: a comparative longitudinal analysis.

Trans and gender-diverse (TGD) adolescents are likely to experience poorer mental health and wellbeing than their cisgender peers. Minority stress theory has developed as a possible explanation for some of this disadvantage: factors such as increased bullying and discrimination lead to excess stress and reduced wellbeing. However, the evidence base remains limited. This study drew on secondary data analysis of the #BeeWell longitudinal cohort over 2 years (N = 26 042, aged 12-13 at time one, T1). We report two unregistered hypotheses relating to T1 (autumn 2021) data which was available at the time of stage-one submission: H1, mean differences in T1 wellbeing; H2, mean differences in T1 minority-related stressors. These are followed by two registered hypotheses relating to T2 (autumn 2022) data: H3, replication of T1 mean differences in T2 wellbeing; H4, predictions were made about the strength of the association between T1 minority-related stressors, controlling for sexuality and T2 wellbeing across T1 gender identity groups. At both time points cis-females, TGD and those who preferred not to say their gender had lower wellbeing than cis-males (CM), with the largest effect evident for the TGD group. TGD adolescents also showed the largest disadvantage (mean difference) compared with CM for minority stressors. Counter to H4 and minority stress theory, gender was not found to moderate the effect of minority stressors on later wellbeing. Our findings highlight the vulnerability of the TGD group in terms of wellbeing and minority stressors and are discussed with relevance for policy and future research.

T1 mapping in population ageing

Abstract Funding Acknowledgements Type of funding sources: None. Background The world’s population is ageing: every country is experiencing growth in both the size and the proportion of older people. Common health states in older age mainly include cardiovascular disease. To ensure that our health system is ready to face this demographic shift, we investigated native and post-contrast T1 mapping as a quantitative method to appraise its clinical potential in older people. Purpose This article aimed to provide reference values of T1 mapping for quantification of the expansion of the extracellular matrix in older people. Methods We retrospectively selected subjects ranged in age from 86 to 101 years old that underwent contrast cardiac magnetic resonance (CMR). All subjects were imaged on a 1.5 T system. T1 measurements were performed with a Modified Look Lockers Inversion (MOLLI) recovery sequence. Regions of interest (ROI) were drawn in the left ventricle for blood T1 measurement and in the interventricular septum. We used T1 data obtained before and after contrast injection. We also measured the volume and function of both ventricles. Rho di Spearman was used for correlations. Results We analysed 29 patients (mean age 88.58±3.13 years old). Mean value of T1 in the blood pool (T1bp) was 1647.43±107.66 before contrast and 357.18±63.94 after contrast. Mean value of T1 in the septum (T1s) was 1012.86±38.41 before contrast and 488.68±69.29 after contrast. Left ventricle (LV) EDVI was 48.11±15.29 ml/m2 and ESVI 16.49±8.59 ml/m2, LV ejection fraction (EF) and stroke volume (SV) were 66.38±9.65 % and 52.39±18.84 ml respectively. Right ventricle (RV) EDVI was 46.44±13.19 ml/m2 and ESVI 16.97±5.93 ml/m2, LV ejection fraction (EF) and stroke volume (SV) were 63.46±8.65 % and 49.29±18.63 ml respectively. A significant negative correlation was found between age and T1s before contrast (r=-0.405 and p = 0.015). Positive correlations were found also between T1s before contrast and LV volumes. Conclusions This study shows a correlation between T1 mapping and population ageing.

Multimodal MRI improves diagnostic accuracy and sensitivity to longitudinal change in amyotrophic lateral sclerosis

BackgroundRecent advances in MRI acquisitions and image analysis have increased the utility of neuroimaging in understanding disease-related changes. In this work, we aim to demonstrate increased sensitivity to disease progression as well as improved diagnostic accuracy in Amyotrophic lateral sclerosis (ALS) with multimodal MRI of the brain and cervical spinal cord.MethodsWe acquired diffusion MRI data from the brain and cervical cord, and T1 data from the brain, of 20 participants with ALS and 20 healthy control participants. Ten ALS and 14 control participants, and 11 ALS and 13 control participants were re-scanned at 6-month and 12-month follow-ups respectively. We estimated cross-sectional differences and longitudinal changes in diffusion metrics, cortical thickness, and fixel-based microstructure measures, i.e. fiber density and fiber cross-section.ResultsWe demonstrate improved disease diagnostic accuracy and sensitivity through multimodal analysis of brain and spinal cord metrics. The brain metrics also distinguished lower motor neuron-predominant ALS participants from control participants. Fiber density and cross-section provided the greatest sensitivity to longitudinal change. We demonstrate evidence of progression in a cohort of 11 participants with slowly progressive ALS, including in participants with very slow change in ALSFRS-R. More importantly, we demonstrate that longitudinal change is detectable at a six-month follow-up visit. We also report correlations between ALSFRS-R and the fiber density and cross-section metrics.ConclusionsOur findings suggest that multimodal MRI is useful in improving disease diagnosis, and fixel-based measures may serve as potential biomarkers of disease progression in ALS clinical trials.

Modern health worries and annoyance from environmental factors are largely unrelated to smoking, alcohol consumption, and physical activity

ObjectiveModern health worries, as well as environmental annoyance from chemical agents, noise, and electromagnetic exposure are associated with symptom reporting and marked affective-behavioural changes. As promotion and protection of health is a primary characteristic of these conditions, it can be expected that they will be related to less risk behaviour (smoking and alcohol consumption) and more health behaviour (physical activity), both cross-sectionally and longitudinally. MethodsHypotheses were tested in a sample of 2336 individuals participating in T1 and T2 data collection (3 years apart) of the Västerbotten Environmental Health Study, Sweden. Health-related behaviours were assessed using single self-report questions. Smoking was measured on a binary (yes-or-no) scale; frequency of alcohol consumption and physical activity was measured on a 5-point and a 4-point scale, respectively. ResultsModern health worries showed no cross-sectional association with the three behaviours, whereas annoyance was typically inversely, very weakly, related to smoking and alcohol consumption. Physical activity was significantly positively associated only with chemical annoyance. None of the variables significantly predicted change of behaviours at T2 after controlling for the respective T1 value and demographic variables. Conclusions: Individuals with high levels of modern health worries and annoyance from various environmental agents are not clearly characterized by a healthier lifestyle. Perhaps they focus on the alleviation of their existing symptoms; alternatively, somatic symptom distress decreases their cognitive-affective resources necessary for a long-term life style change.

Evaluation of skeletal changes in glenoid fossa, condylar head and articular space following fixed functional appliance therapy using cone beam computed tomography – A clinical prospective study

This study was conducted to evaluate skeletal changes in glenoid fossa, condylar head and articular space following Powerscope appliance therapy using CBCT.This study included twenty patients (age group of 11-15 years) having Class II Division 1 skeletal &amp; dental malocclusion. A pre-treatment CBCT scan (T1) of both TMJs was taken. Following leveling &amp; aligning, Powerscope appliance was inserted, which was sequentially activated using crimpable shims until edge-to-edge bite was obtained. After completion of phase 1 of treatment, another CBCT scan (T2) was taken. Condylar position, length, height, glenoid fossa &amp; articular space measurements were obtained from pre- &amp; post-treatment CBCT scans and data obtained were statistically analysed and compared by Paired-t test.Comparison between T1 &amp; T2 data showed that the condyles were shifted anteriorly by 1.08 mm, condylar length and height increased by 0.26 mm and 0.71 mm, respectively. Glenoid fossa and anterior articular space decreased by 1.50⁰ and 0.23 mm, whereas, middle and posterior articular spaces increased linearly by 2.55 mm and 1.85 mm, respectively.Powerscope shifted the condyle anteriorly, increased its length and height, and reduced the glenoid fossa angle. Anterior articular space decreased whereas middle and posterior articular spaces increased.

Axon fiber orientation as the source of T1 relaxation anisotropy in white matter: A study on corpus callosum in vivo and ex vivo.

Recent studies indicate that T1 in white matter (WM) is influenced by fiber orientation in B0 . The purpose of the study was to investigate the interrelationships between axon fiber orientation in corpus callosum (CC) and T1 relaxation time in humans in vivo as well as in rat brain ex vivo. Volunteers were scanned for relaxometric and diffusion MRI at 3 T and 7 T. Angular T1 plots from WM were computed using fractional anisotropy and fiber-to-field-angle maps. T1 and fiber-to-field angle were measured in five sections of CC to estimate the effects of inherently varying fiber orientations on T1 within the same tracts in vivo. Ex vivo rat-brain preparation encompassing posterior CC was rotated in B0 and T1 , and diffusion MRI images acquired at 9.4 T. T1 angular plots were determined at several rotation angles in B0 . Angular T1 plots from global WM provided reference for estimated fiber orientation-linked T1 changes within CC. In anterior midbody of CC in vivo, where small axons are dominantly present, a shift in axon orientation is accompanied by a change in T1 , matching that estimated from WM T1 data. In CC, where large and giant axons are numerous, the measured T1 change is about 2-fold greater than the estimated one. Ex vivo rotation of the same midsagittal CC region of interest produced angular T1 plots at 9.4 T, matching those observed at 7 T in vivo. These data causally link axon fiber orientation in B0 to the T1 relaxation anisotropy in WM.

Analysis of Adsorbed Polyphosphate Changes on Milled Titanium Dioxide, Using Low-Field Relaxation NMR and Photoelectron Spectroscopy.

In this study, changes in the adsorbed amount and surface structure of sodium hexametaphosphate (SHMP) were investigated for aluminum-doped TiO2 pigment undergoing milling. Relaxation NMR was utilized as a potential at-line technique to monitor the effect of milling on surface area and surface chemistry, while XPS was used primarily to consider the dispersant structure. Results showed that considerable amounts of weakly adsorbed SHMP could be removed with washing, and the level of dispersant removal increased with time, highlighting destructive effects of sustained high-energy milling. Nonetheless, there were no significant chemical changes to the dispersant, although increases to the bridging oxygen (BO) peak full width at half-maximum (FWHM) suggested some chemical degradation was occurring with excess milling. Relaxation NMR revealed a number of important features. Results with unmilled material indicated that dispersant adsorption could be tracked with pseudo-isotherms using the relative enhancement rate (Rsp), where the Rsp decreased with dispersant coverage, owing to partial blocking of the quadrupolar surface aluminum. Milled samples were also tracked, with very accurate calibrations of surface area possible from either T1 or T2 relaxation data for systems without dispersant. Behavior was considerably more complicated with SHMP, as there appeared to be an interplay between the dispersant surface coverage and relaxation enhancement from the surface aluminum. Nevertheless, findings highlight that relaxation NMR could be used as a real-time technique to monitor the extent of milling processes, so long as appropriate industrial calibrations can be achieved.

The Multi-dimensional Assessment of Suicide Risk in Chronic illness-20 (MASC-20): Development and validation

BackgroundWe developed and tested the psychometric properties of the Multi-dimensional assessment of suicide risk in chronic illness-20 (MASC-20), which assess suicidal behavior (SB), and its associated distress in chronic physical illness (CPI). MethodsItems were developed by incorporating inputs from patient interviews, a review of existing instruments, and expert consultations. Pilot testing with 109 patients and field testing with 367 patients with renal, cardiovascular, and cerebrovascular diseases were conducted. We analyzed Time (T) 1 data to select items and T2 data to examine psychometric properties. ResultsForty preliminary items were selected through pilot testing; 20 were finalized from field testing. Optimal internal consistency (α = 0.94) and test-retest reliability (Intra class correlation coefficient = 0.92) of the MASC-20 supported reliability. Good fit of the four-factor model (physical distress, psychological distress, social distress, and SB) from exploratory structural equation modeling demonstrated factorial validity. Its correlations with MINI suicidality (r = 0.59) and the Schedule of Attitudes Toward Hastened Death-abbreviated scores (r = 0.62) indicated convergent validity. Higher MASC-20 scores in patients with clinical levels of depression and anxiety and low health status demonstrated known-group validity. The MASC-20 distress score predicted SB beyond known SB risk factors, supporting incremental validity. A cutoff score of 16 was optimal for identifying suicide risk. The area under the curve was within a moderately accurate range. The sum of sensitivity and specificity (1.66) indicated diagnostic utility. LimitationsMASC-20's applicability to other patient populations and its sensitivity to change requires testing. ConclusionsThe MASC-20 appears to be a reliable and valid tool for assessing SB in CPI.

Quantitative analysis of the morphometric analysis program MAP in patients with truly MRI-negative focal epilepsy

ObjectiveIn the presurgical evaluation of epilepsy, identifying the epileptogenic zone is challenging if magnetic resonance imaging (MRI) is negative. Several studies have shown the benefit of using a morphometric analysis program (MAP) on T1-weighted MRI scans to detect subtle lesions. MAP can guide a focused re-evaluation of MRI to ultimately identify structural lesions that were previously overlooked. Data on patients where this additional review after MAP analysis did not reveal any lesions is limited. Here we evaluate the diagnostic yield of MAP in a large group of truly MRI-negative patients. MethodsWe identified 68 patients with MRI-negative focal epilepsy and clear localization of the epileptogenic zone by intracranial EEG or postoperative seizure freedom. High resolution 3D T1 data of patients and 73 healthy controls were acquired on a 3 T scanner. Morphometric analysis was performed with MAP software, creating five z-score maps, reflecting different structural properties of the brain and a patient’s deviation from the control population, and a neural network-based focal cortical dysplasia probability map. Ten brain regions were specified to quantify whether MAP findings were located in the correct region. Receiver operating characteristic (ROC) analyses were performed to identify the optimal thresholds for each map. ResultsMAP-guided visual re-evaluation of the original MRI revealed overlooked lesions in three patients. The remaining 65 truly MRI-negative patients were included in the statistical analysis. At the optimal thresholds, maximum sensitivity was 84 %, with 35 % specificity. Balanced accuracy (arithmetic mean of sensitivity and specificity) of the respective maps ranged from 51 % to 60 %, creating three to six times more false positive than true positive findings. ConclusionThis study confirms that MAP is useful in detecting previously overlooked subtle structural lesions. However, in truly MRI-negative patients, the additional diagnostic yield is very limited.

NMR-based petrophysical parameter calculation with sparse inversion in tight reservoirs

Porosity, permeability, and saturation are important parameters reflecting the petrophysical properties of cores. The petrophysical parameters can be calculated from the inverted nuclear magnetic resonance (NMR) spectra. However, the continuous relaxation time distribution in the traditional NMR spectra is inconsistent with the sparse NMR relaxation signatures of the pore fluid. In this paper, a sparse inversion method was proposed to process NMR data in tight reservoirs, and the petrophysical parameters were calculated from the sparse NMR spectra. In the sparse inversion process, the relaxation time range of the core was first determined, only one new relaxation time was added to the sparse inversion in each iteration, and then the insignificant signal was eliminated. The signal amplitudes of sparse NMR spectra are constrained by the amplitude of the first echo to avoid the influence of noise. Compared with the traditional NMR spectra, the relaxation time is sparse and unfixed in the sparse NMR spectra. The T2 data of tight sandstone and T1-T2 data of shale were processed, and petrophysical parameters were evaluated to verify the effectiveness of the proposed method. The results indicate that the sparse NMR spectra can be better used to accurately calculate the petrophysical parameters in tight reservoirs, including porosity, permeability, and saturation.