Tag: nevin manimala

Orthop Res Rev. 2022 Nov 16;14:429-435. doi: 10.2147/ORR.S387104. eCollection 2022.

ABSTRACT

Minimally invasive sacroiliac joint (SIJ) fusion is the preferred surgical method for managing patients with recalcitrant, chronically severe SIJ pain and dysfunction refractory to conservative medical measures. The primary surgical objective of all minimally invasive SIJ fusion procedures is to provide immediate stabilization within the joint space to support osseous consolidation and the development of a mechanically solid arthrodesis. The intra-articular surgical approach to the SIJ with allograft bone placement utilizes a trajectory and easily identifiable landmarks that allow the surgeon to control the risk of violating important neuro-vascular structures. The intra-articular approach can employ a superior or inferior operative trajectory, with the former restricted to allograft placement in the ligamentous portion of the SIJ. The inferior approach utilizes decortication to surgically create a channel originating in the purely articular portion of the joint space allowing for truly intra-articular implant placement within the osseous confines of the ilium and sacrum. Positioning the implant along the natural joint line and securing it within the underlying sub-chondral bone, mortise and tenon fashion provides stabilization and large surface area contact at the bone implant interface. The inferior, intra-articular approach also places the implant perpendicular to the S1 endplate, near the sacral axis of rotation, which addresses the most significant biomechanical forces across the joint. Short-term, post-surgical observational data from a 57 patient multi-center registry using the inferior, intra-articular approach show uniform and statistically significant improvement in all clinical outcomes (p < 0.001 for all comparisons), including an average 3-point improvement in back pain severity from 6.8 preoperatively to 3.8 at 6 months. Further clinical evaluation with longer-term follow-up of the inferior, intra-articular SIJ fusion procedure is encouraged.

PMID:36420375 | PMC:PMC9677508 | DOI:10.2147/ORR.S387104

Sci Rep. 2022 Nov 23;12(1):20151. doi: 10.1038/s41598-022-21085-8.

ABSTRACT

Autism spectrum disorder (ASD) is a lifelong neurodevelopmental disorder, with only a small proportion of people obtaining optimal outcomes. We do not know if children with ASD exhibit abnormalities in the white matter (WM) microstructure or if this pattern would predict ASD prognosis in a longitudinal study. 182 children with ASD were recruited for MRI and clinical assessment; 111 completed a four-year follow-up visit (30 with optimal outcomes, ASD-; 81 with persistent diagnosis, ASD+). Additionally, 72 typically developing controls (TDC) were recruited. The microstructural integrity of WM fiber tracts was revealed using tract-based spatial statistics (TBSS) and probabilistic tractography analyses. We examined the neuroimaging abnormality associated with ASD and its relationship to ASD with optimal outcome. The ASD+ and TDC groups were propensity score matched to the ASD- group in terms of age, gender, and IQ. TBSS indicated that children with ASD exhibited abnormalities in the superior longitudinal fasciculus (SLF), inferior longitudinal fasciculus (ILF), and extending to the anterior thalamic radiation (ATR) and cingulum; whereas the ASD+ group showed more severe abnormalities than the ASD- group. Probabilistic tractography analysis revealed that ASD+ group exhibited lower Fractional Anisotropy (FA) of the left superior thalamic radiation (STR L) than ASD- group, and that FA value of the STR L was a significant predictor of optimal outcome (EX(B), 6.25; 95% CI 2.50-15.63; p < 0.001). Children with ASD showed significant variations in SLF_L and STR_L, and STR_L was a predictor of ‘ASD with optimal outcome’. Our findings may aid in comprehension of the mechanisms of ‘ASD with optimal outcome’.

PMID:36418886 | DOI:10.1038/s41598-022-21085-8

Anal Sci. 2022 Nov 23. doi: 10.1007/s44211-022-00225-0. Online ahead of print.

ABSTRACT

A commercial X-ray computed tomography (CT) apparatus using a quasi-monochromatic beam was utilized for density estimations and comparisons of a fragmented single fiber. The validation of quasi-monochromaticity of the X-ray source was investigated by radiograph measurements. For the case of a transmittance higher than 50%, the contribution of Cu Kα characteristic X-rays was dominant. To realize a sufficient statistical quality, an attempt to increase the number of averaged voxels was demonstrated using the neighboring slices of the 3D-CT image. A minimum value of the coefficient of variation (CV) was achieved using multiple images rather than using a single image. The observed values of the inverse of the transmitted X-ray intensity (CT value) of the polymers showed a fairly good relationship with their density. An analytical curve derived from measurements of reference samples of known densities could provide the relative density of an unknown fragmented fiber down to the size of 30 μm in diameter and 35 μm in length. The CV of the estimated density was from 1.5 to 2%, which was estimated from the CV of CT values. Moreover, the correlation of CT values was improved with the linear absorption coefficient than the density. A better performance of discrimination of polymers including fibers might be realized with the difference of linear absorption coefficients for X-rays.

PMID:36418842 | DOI:10.1007/s44211-022-00225-0

Environ Sci Pollut Res Int. 2022 Nov 23. doi: 10.1007/s11356-022-24003-7. Online ahead of print.

ABSTRACT

This paper presents new results on the gasification of spent pot lining (SPL) waste material generated in the primary aluminium smelting industry. The main objective is to test the performance of the gasification process of treated SPL materials and to develop an optimization method to maximize the quality of syngas fuel. The novelty of this study is the development of statistical models to predict the syngas composition and the gasification performance indicators during the SPL waste materials thermal conversion process. Modelling and simulation analysis are performed to convert the SPL solid materials to syngas fuel. The percentage of hydrogen (H₂) and carbon monoxide (CO) in the syngas fuel, the cold gasification efficiency (CGE) and the carbon conversion (CC) are determined. The response surface methodology (RSM) is used for the optimization of the performance of the gasification process. The effects of the input factors such as the temperature, the equivalence ratio and the steam to fuel ratio on the output variables (H₂ and CO in the syngas, the CGE and the CC) are determined. The optimization results show that the optimized operating parameters to maximize the H₂, CO, CGE and CC were T = 1200 °C, ER = 0.1 and SFR = 1.29, respectively. The optimum values for the H₂, CO, CGE and CC were 37.2%, 22.2%, 79.75% and 97.7%, respectively. New correlations for the variation of the output variables versus the input factors are also presented.

PMID:36418819 | DOI:10.1007/s11356-022-24003-7

Int Ophthalmol. 2022 Nov 23. doi: 10.1007/s10792-022-02571-4. Online ahead of print.

ABSTRACT

PURPOSE: To investigate the advantages/disadvantages of a 1.0 D toric IOL vs spherical IOL after regular phacoemulsification in eyes with preoperative astigmatism ≤ 1 D.

METHODS: Retrospective comparative series involving pseudophakic eyes with preoperative topographic astigmatism ≤ 1.0 D implanted either with monofocal 1.0 D Toric IOL (T-group), or with spherical IOL (S-group). The postoperative refractive astigmatism (PRA, i.e. surgically induced + corneal) was the main outcome; also considered in the analyses were the uncorrected and best-corrected distance visual acuity (VA). The data were referred to the last postoperative follow-up visit, 2 to 4 months after surgery.

RESULTS: A total of 60 eyes were included: 30 in the T-group and 30 in the S-group, matched for patient’s age, laterality, and axial length. Before surgery, the mean corneal astigmatism was 0.62 ± 0.39 D in the T-group and 0.54 ± 0.33 D in the S-group (p = 0.4). In the S-group, PRA was 0.73 ± 0.37 D, higher than the corresponding preoperative corneal astigmatism (p = 0.040). In the T-group, PRA was 0.58 ± 0.31 D; the variation was not statistically significant. Uncorrected VA was significantly better in the T-group vs the S-group (p = 0.007), and the best-corrected VA was comparable in the two groups.

CONCLUSION: The present study indicated that in eyes with very low preoperative astigmatism, 1.0 D toric IOLs were able to limit the increase of the PRA instead of those observed with the spherical IOLs. This could support the better uncorrected VA recorded in the T-group.

PMID:36418805 | DOI:10.1007/s10792-022-02571-4

Psychometrika. 2022 Nov 23. doi: 10.1007/s11336-022-09888-0. Online ahead of print.

ABSTRACT

The measurement of latent traits and investigation of relations between these and a potentially large set of explaining variables is typical in psychology, economics, and the social sciences. Corresponding analysis often relies on surveyed data from large-scale studies involving hierarchical structures and missing values in the set of considered covariates. This paper proposes a Bayesian estimation approach based on the device of data augmentation that addresses the handling of missing values in multilevel latent regression models. Population heterogeneity is modeled via multiple groups enriched with random intercepts. Bayesian estimation is implemented in terms of a Markov chain Monte Carlo sampling approach. To handle missing values, the sampling scheme is augmented to incorporate sampling from the full conditional distributions of missing values. We suggest to model the full conditional distributions of missing values in terms of non-parametric classification and regression trees. This offers the possibility to consider information from latent quantities functioning as sufficient statistics. A simulation study reveals that this Bayesian approach provides valid inference and outperforms complete cases analysis and multiple imputation in terms of statistical efficiency and computation time involved. An empirical illustration using data on mathematical competencies demonstrates the usefulness of the suggested approach.

PMID:36418780 | DOI:10.1007/s11336-022-09888-0

Int J Comput Assist Radiol Surg. 2022 Nov 23. doi: 10.1007/s11548-022-02792-z. Online ahead of print.

ABSTRACT

INTRODUCTION: Practicing endoscopic procedures is fundamental for the education of clinicians and the benefit of patients. Despite a diverse variety of model types, there is no system simulating anatomical restrictions and variations in a flexible and atraumatic way. Our goal was to develop and validate a new modelling approach for adhesion forces between colon and abdominal wall.

METHODS: An inlay for a standard mechanical trainer was designed and 3D printed. Colon specimens were fixed to the inlay along colon ascendens (CA) and colon descendens (CD) by a vacuum. Our system, which we refer to as Colonoscopy Vacuum Model (CoVaMo), was validated with 11 test persons with varying level of expertise. Each performed one colonoscopy and one polypectomy in the CoVaMo and in the Endoscopic Laparoscopic Interdisciplinary Training Entity (ELITE). Achieved adhesion forces, times required to fulfill different tasks endoscopically and a questionnaire, assessing proximity to reality, were recorded.

RESULTS: Mean adhesion forces of 37 ± 7 N at the CA and 30 ± 15 N at the CD were achieved. Test subjects considered CoVaMo more realistic than ELITE concerning endoscope handling and the overall anatomy. Participants needed statistically significantly more time to maneuver from anus to flexura sinistra in CoVaMo (377 s ± 244 s) than in ELITE (58 s ± 49 s).

CONCLUSION: We developed a training environment enabling anatomically and procedural realistic colonoscopy training requiring participants to handle all endoscope features in parallel. Fixation forces compare to forces needed to tear pig colon off the mesentery. Workflow and inlay can be adapted to any arbitrary ex vivo simulator.

PMID:36418762 | DOI:10.1007/s11548-022-02792-z

J Med Syst. 2022 Nov 24;46(12):102. doi: 10.1007/s10916-022-01891-3.

ABSTRACT

INTRODUCTION: Surgical skill assessment utilises direct observation and feedback by an expert which is potentially subjective, therefore obtaining objective data for hand and eye tracking is essential. Our aim was to evaluate a wearable mixed reality (MR) headset in these domains.

METHODS: Participants with differing levels of surgical expertise [novice (N), intermediate (I) & expert (E)] performed 4 simulated surgical tasks; 2 general dexterity (tasks 1&2) and 2 surgical skills (tasks 3&4) wearing the MR headset capturing their hand and eye movements (median & range). Metrics included hand path length and the speed of each index or thumb tip. Gaze data were also captured. Participant demographics, prior expertise and current experience were captured with an electronic survey. Data were analysed with a Shapiro-Wilk test or ANOVA as appropriate. A p-value of < 0.05 was significant.

RESULTS: Thirty-six participants were analysed (N = 18, I = 8, E = 8). Tasks 1&2 revealed 2 speed outcomes (left index and left-hand speed) which were significant. For tasks 3&4, various outcomes were significant: path length for left hand (N:45 cm vs. I:31 cm vs. E:27 cm, p = 0.03) and right hand (N:48 cm vs. I:29 cm vs. E:28 cm, p = 0.01) and total time (N:456s vs. I:292 vs. E: 245, p = 0.0002). With left-hand-tying, average path length (N:61 cm vs. I:39 vs. E:36, p = 0.04), average speed (N:11 cm/s vs. I:23 vs. E:24, p = 0.03), and total time (N:156s vs. I:43 vs. E:37, p = 0.003) were significant. The gaze-tracking was not statistically significant.

CONCLUSION: The MR headset can be utilised as a valid tool for surgical performance assessment. Outcomes including path length and speed can be valuable metrics captured by the MR Headset during the task completion for detecting surgical proficiency.

PMID:36418760 | DOI:10.1007/s10916-022-01891-3

Acta Neurochir (Wien). 2022 Nov 23. doi: 10.1007/s00701-022-05422-4. Online ahead of print.

ABSTRACT

OBJECTIVE: The purpose of the study was to investigate the feasibility and preliminary effects of unilateral biportal endoscopic extreme transforaminal lumbar interbody fusion(UBE-eXTLIF) with large cage combined with endoscopic unilateral pedicle screw fixation for lumbar degenerative diseases.

METHODS: Patients with lumbar degenerative diseases who received UBE-eXTLIF with large cage combined with endoscopic unilateral pedicle screw fixation from June 2022 to July 2022 were retrospectively analyzed, including 4 females and 1 males. The clinical symptoms and signs were consistent with the imaging changes. We recorded operation time, length of postoperative hospital stay, and complications. Visual Analogue Scale (VAS), Oswestry Disability Index (ODI), and modified Macnab scale was used to evaluate the clinical efficacy at preoperative, postoperative 1 month, and the last follow-up.

RESULTS: The operation was successfully completed in all cases. The operation time was 150-180 min, with an average of 164.60 ± 12.03 min. No serious complications such as dural tears and vascular and nerve injuries occurred during operation. All the patients got out of bed 1-3 days after surgery and were hospitalized 4-5 days after surgery, with an average of 4.20 ± 0.45 days. Preoperative VAS scores of low back pain were 6.20 ± 0.84 and respectively decreased to 2.20 ± 0.45 and 1.40 ± 0.55 at postoperative 1 month and at the last follow-up, and the difference was statistically significant (P < 0.05). Preoperative VAS scores of lower limb pain were 4.60 ± 2.61 and respectively decreased to 1.00 ± 0.71 and 0.60 ± 0.55 at postoperative 1 month and at the last follow-up, and the difference was statistically significant (P < 0.05). Preoperative ODI scores were 62.00 ± 3.16 and respectively decreased to 38.00 ± 1.41 and 32.40 ± 3.29 at postoperative 1 month and at the last follow-up, and the difference was statistically significant (P < 0.05). According to the modified Macnab criteria, the final outcome was excellent in 4 cases and good in 1 case. Five patients could return to normal activities within 3 weeks.

CONCLUSIONS: UBE-eXTLIF with large cage combined with endoscopic unilateral pedicle screw fixation can achieve excellent clinical results and may become a new minimally invasive endoscopic fusion method for lumbar degenerative diseases.

PMID:36418757 | DOI:10.1007/s00701-022-05422-4

J Med Syst. 2022 Nov 23;46(12):100. doi: 10.1007/s10916-022-01890-4.

ABSTRACT

In clinical practice, many drug therapies are associated with prolongation of the QT interval. In literature, estimation of the risk of prescribing drug-induced QT prolongation is mainly executed by means of logistic regression; only one paper reported the use of machine learning techniques. In this paper, we compare the performance of both techniques on the same dataset. High risk for QT prolongation was defined as having a corrected QT interval (QTc) ≥ 450 ms or ≥ 470 ms for respectively male and female patients. Both conventional statistical methods (CSM) and machine learning techniques (MLT) were used. All algorithms were validated internally and with a hold-out dataset of respectively 512 and 102 drug-drug interactions with possible drug-induced QTc prolongation. MLT outperformed the best CSM in both internal and hold-out validation. Random forest and Adaboost classification performed best in the hold-out set with an equal harmonic mean of sensitivity and specificity (HMSS) of 81.2% and an equal accuracy of 82.4% in a hold-out dataset. Sensitivity and specificity were both high (respectively 75.6% and 87.7%). The most important features were baseline QTc value, C-reactive protein level, heart rate at baseline, age, calcium level, renal function, serum potassium level and the atrial fibrillation status. All CSM performed similarly with HMSS varying between 60.3% and 66.3%. The overall performance of logistic regression was 62.0%. MLT (bagging and boosting) outperform CSM in predicting drug-induced QTc prolongation. Additionally, 19.2% was gained in terms of performance by random forest and Adaboost classification compared to logistic regression (the most used technique in literature in estimating the risk for QTc prolongation). Future research should focus on testing the classification on fully external data, further exploring potential of other (new) machine and deep learning models and on generating data pipelines to automatically feed the data to the classifier used.

PMID:36418746 | DOI:10.1007/s10916-022-01890-4