Nevin Manimala

Sensors (Basel). 2024 Apr 21;24(8):2648. doi: 10.3390/s24082648.

ABSTRACT

A systematic study of the nonlinear response of Silicon Photomultipliers (SiPMs) was conducted through Monte Carlo (MC) simulations. The MC code was validated against experimental data for two different SiPMs. Nonlinearity mainly depends on the balance between the photon rate and the pixel recovery time. Additionally, nonlinearity has been found to depend on the light pulse shape, the correlated noise, the overvoltage dependence of the photon detection efficiency, and the impedance of the readout circuit. Correlated noise has been shown to have a minor impact on nonlinearity, but it can significantly affect the shape of the SiPM output current. Considering these dependencies and a previous statistical analysis of the nonlinear response of SiPMs, two phenomenological fitting models were proposed for exponential-like and finite light pulses, explaining the roles of their various terms and parameters. These models provide an accurate description of the nonlinear responses of SiPMs at the level of a few percentages for a wide range of situations.

PMID:38676265 | DOI:10.3390/s24082648

Sensors (Basel). 2024 Apr 20;24(8):2643. doi: 10.3390/s24082643.

ABSTRACT

The study presents a promising approach to enzymatic kinetics using Electrochemical Impedance Spectroscopy (EIS) to assess fundamental parameters of modified enteropeptidases. Traditional methods for determining these parameters, while effective, often lack versatility and convenience, especially under varying environmental conditions. The use of EIS provides a novel approach that overcomes these limitations. The enteropeptidase underwent genetic modification through the introduction of single amino acid modifications to assess their effect on enzyme kinetics. However, according to the one-sample t-test results, the difference between the engineered enzymes and hEKL was not statistically significant by conventional criteria. The kinetic parameters were analyzed using fluorescence spectroscopy and EIS, which was found to be an effective tool for the real-time measurement of enzyme kinetics. The results obtained through EIS were not significantly different from those obtained through traditional fluorescence spectroscopy methods (p value >> 0.05). The study validates the use of EIS for measuring enzyme kinetics and provides insight into the effects of specific amino acid changes on enteropeptidase function. These findings have potential applications in biotechnology and biochemical research, suggesting a new method for rapidly assessing enzymatic activity.

PMID:38676260 | DOI:10.3390/s24082643

Arch Oral Biol. 2024 Apr 24;163:105981. doi: 10.1016/j.archoralbio.2024.105981. Online ahead of print.

ABSTRACT

OBJECTIVES: An ex-vivo study was aimed at (i) programming clinically validated robot three-year random toothbrushing, (ii) evaluating cervical macro- and microwear patterns on all tooth groups of different functional age, (iii) documenting and codificating wear related morphological features at the cemento-enamel junction in young teeth and on roots in older teeth.

DESIGN: Following ethical approval random toothbrushing (44 strokes per tooth horizontally, rotating, vertically; 2x/d) with manual toothbrushes and low-abrasive dentifrice was performed in an artificial oral cavity with brushing-force 3.5 N on 14 extracted human teeth. Morphological features were examined by SEM at baseline and after simulated 3 years using the replication technique. 3D-SEM analyses were carried out with a four-quadrant back scattered electron detector. Wilcoxon-Mann-Whitney-test was used for statistical analyses.

RESULTS: 3-year random toothbrushing with horizontal, rotating and vertical brushing movements revealed morphological features classified as four enamel patterns, one dentin pattern and three cervical patterns. Negative impacts were enamel, cementum and dentin loss. Positive impact on oral health was removing dental calculus and straightening cervical traumatic and iatrogenic damages. The volume loss varied from x̅=34.25nl to x̅=87.75nl. Wear extended apically from 100 to 1500 micrometres.

CONCLUSION: Robot simulated toothbrushing in an artificial oral cavity, with subsequent SEM and 3D-SEM assessment, elucidated both negative and oral health-contributing micromorphology patterns of cervical wear after simulated 3-year random toothbrushing. Cervical macro- and microwear of cementum revealed, for the first time, what we describe as overhanging enamel peninsulas and enamel islands on roots in young teeth, but no enamel islands on roots from older teeth after root cementum loss. In contrast, many older teeth exhibited enamel peninsulas.

PMID:38669743 | DOI:10.1016/j.archoralbio.2024.105981

Lung Cancer. 2024 Apr 23;191:107798. doi: 10.1016/j.lungcan.2024.107798. Online ahead of print.

ABSTRACT

OBJECTIVES: In this study, we explored the clinical outcomes of non-small cell lung cancer (NSCLC) patients with EGFR Exon20 in-frame insertions (Exon20ins), and the impact of the location of Exon20ins on these clinical outcomes.

MATERIALS AND METHODS: The efficacies of current systemic therapies in NSCLC patients harboring Exon20ins were investigated using a large-scale clinico-genomic database of LC-SCRUM-Asia, and compared with that of amivantamab in the CHRYSALIS trial.

RESULTS: Of the 11,397 patients enrolled in LC-SCRUM-Asia, Exon20ins were detected in 189 patients (1.7 %). Treatment with classical EGFR tyrosine-kinase inhibitors (classical TKIs) was associated with a significantly shorter progression-free survival (PFS) in NSCLC patients with Exon20ins as compared with Exon19 deletions and L858R. Post platinum-based chemotherapy, classical TKIs and immune checkpoint inhibitors (ICIs) were associated with a shorter PFS than with docetaxel in patients with Exon20ins (HR [95 % CI]; TKIs vs docetaxel, 2.16 [1.35-3.46]; ICIs vs docetaxel, 1.49 [1.21-1.84]). Patients treated with amivantamab in the CHRYSALIS trial showed a risk reduction in PFS and overall survival as compared with LC-SCRUM-Asia patients treated with docetaxel, classical TKIs, or ICIs. Among the 189 patients, Exon20ins were classified as near-loop or far-loop insertions in 115 (61 %) and 56 (30 %) patients, respectively. Treatment with osimertinib was associated with a longer PFS in patients with Exon20ins in near-loop as compared with far-loop (median, 5.6 vs. 2.0 months; HR [95 % CI], 0.22 [0.07-0.64]).

CONCLUSIONS: After platinum-based chemotherapy, classical TKIs and ICIs are less effective in NSCLC patients with Exon20ins, and amivantamab may be a promising targeted therapy. There is a possibility that the location of Exon20ins has an impact on the efficacy of TKIs.

PMID:38669727 | DOI:10.1016/j.lungcan.2024.107798

Environ Int. 2024 Apr 23;187:108686. doi: 10.1016/j.envint.2024.108686. Online ahead of print.

ABSTRACT

The blood levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) have been thoroughly investigated in Greek children from the Rhea birth cohort study. This investigation aimed to assess exposure levels, explore their possible relationship with children’s age and sex, and indicate potential sources of exposure. Exposure patterns and common sources of PCBs and OCPs were analyzed using bivariate and multivariate statistics. A total of 947 blood samples from study participants were analyzed for OCP and PCB exposure, with 375 samples collected at 4 years old, 239 at 6.5 years old, and 333 at 11 years old. Elevated levels of DDE were observed in 6.5-year-old children compared to corresponding levels in other European countries. Higher levels of DDE were found in 4-year-old children, with the lowest concentrations in the 11-year-old group. The DDT/DDE ratio was consistently less than 1 among all the examined subjects. These results indicate exposure to DDT and DDE both in utero and through breastfeeding and dietary intake. For the entire cohort population, the highest concentration was determined for PCB 28, followed by PCBs 138, 153, and 180. The sum of the six indicator PCBs implied low exposure levels for the majority of the cohort population. Spearman correlations revealed strong associations between PCBs and OCPs, while principal component analysis identified two different groupings of exposure. DDE exhibited a correlation with a series of PCBs (153, 156, 163, 180), indicating a combined OCP-PCB source, and an anticorrelation with others (52, 28, 101), implying a separate and competing source.

PMID:38669722 | DOI:10.1016/j.envint.2024.108686

J Neurosurg. 2024 Apr 26:1-7. doi: 10.3171/2024.1.JNS232342. Online ahead of print.

ABSTRACT

OBJECTIVE: Intraoperative MRI (iMRI) is the gold-standard technique for intraoperative evaluation of the extent of resection in brain tumor surgery. Unfortunately, it is currently available at only a few neurosurgical centers. A commercially available software, Virtual iMRI Cranial, provides an elastic fusion between preoperative MRI and intraoperative CT (iCT). The aim of this study was to evaluate the accuracy of this software in determining the presence of residual tumor.

METHODS: Virtual iMRI was performed in patients who underwent iCT after intracranial tumor resection. The results of the software in terms of presence or absence of tumor residual were then compared with postoperative MRI performed within 48 hours after surgery to evaluate the diagnostic accuracy of virtual iMRI.

RESULTS: Sixty-six patients were included in the present study. The virtual iMRI findings were concordant with the postoperative MRI data in 35 cases (53%) in the detection of tumor residual (p = 0.006). No false-negative findings (i.e., presence of residual on postoperative MRI and absence of residual on virtual iMRI) were encountered. Virtual iMRI had a sensitivity of 1 (95% CI 0.86-1), specificity of 0.26 (95% CI 0.14-0.42), positive predictive value of 0.44 (95% CI 0.3-0.58), and negative predictive value of 1 (95% CI 0.72-1). Subgroup analysis revealed that the virtual iMRI findings were concordant with postoperative MRI findings in all cases (n = 9) of lower-grade glioma (LGG) with a sensitivity of 1 (95% CI 0.59-1) and a specificity of 1 (95% CI 0.16-1) (p = 0.003); a statistically significant association was also found for grade 4 gliomas with a sensitivity of 1 (95% CI 0.69-1) and a specificity of 0.33 (95% CI 0.08-0.7) (p = 0.046) (19 patients). No significant association was found when considering meningiomas or metastases.

CONCLUSIONS: The commercially available virtual iMRI can predict the presence or absence of tumor residual with high sensitivity. The diagnostic accuracy of this method was higher in LGGs and much lower for meningiomas or metastases; these findings must be evaluated in prospective studies in a larger population.

PMID:38669708 | DOI:10.3171/2024.1.JNS232342

J Neurosurg. 2024 Apr 26:1-9. doi: 10.3171/2024.1.JNS232508. Online ahead of print.

ABSTRACT

OBJECTIVE: Determining the underlying etiology of acute vertebrobasilar artery occlusion (VBAO) is crucial for selecting an appropriate treatment approach. The authors aimed to investigate the distribution of etiology and the association with functional outcomes in patients with acute VBAO who underwent endovascular treatment in which atherosclerosis, small-vessel disease, cardiac pathology, other causes, and dissection (ASCOD) phenotyping was used.

METHODS: A retrospective study was conducted at 21 centers in China, involving patients with VBAO who received endovascular treatment within 24 hours of the estimated occlusion time. In the ASCOD phenotyping, each phenotype is graded based on the following categories: 1, likely to be causal; 2, uncertain if causal; and 3, unlikely to be causal. The authors defined a single possible cause as a cause graded 1 in a single domain, and multiple possible causes were graded 1 or 2 regardless of overlap. The primary outcome was unfavorable outcome (modified Rankin Scale [mRS] score of 3-6) at 90 days. The secondary outcomes included shift of mRS score at 90 days, 90-day mortality, successful reperfusion, and National Institutes of Health Stroke Scale score at 24 hours. Multivariable regression analysis was used to assess the association between etiological subtypes and functional outcomes. Multivariate competing-risk regression analysis was performed to analyze the association between etiological subtypes and the risk of recurrent stroke.

RESULTS: A total of 577 patients were included in this study. Of these, 521 (90%) had a single possible cause. The most common etiology was A1 (382 cases, 73%), followed by C1 (111 cases, 21%) and O1 (28 cases, 5%-in this study the other causes and dissection subtypes were categorized under the umbrella term of “O” causes). Similar patterns were observed in the multiple possible causes. In the baseline characteristics of the cohort, as rescue therapy, stenting was more frequently used in patients in the A1 group than in the C1 group (53.2% vs 41.7%; p < 0.01). The proportion of atherosclerosis-type etiology increased when the occlusion was located more proximally (p < 0.01). Compared to the A1 group, patients in the C1 group had a lower incidence of unfavorable outcome (OR 0.42, 95% CI 0.24-0.73), which was less likely to shift to a worse mRS score (OR 0.60, 95% CI 0.39-0.91). The O1 subtype was not associated with unfavorable outcome (OR 1.35, 95% CI 0.46-4.01), whereas patients with the O1 subtype were more likely to shift to worse mRS score (OR 2.39, 95% CI 1.09-5.25) and to have a higher 90-day mortality rate (OR 2.60, 95% CI 1.07-6.31). Furthermore, there was no significant association between single etiological subtypes and stroke recurrence within 1 year.

CONCLUSIONS: The most common etiology in patients with VBAO was atherosclerosis, followed by cardiac pathology and other. Compared to the A1 subgroup, the C1 subgroup showed better functional outcomes, whereas the O1 subgroup showed worse outcomes. Additionally, there was no statistically significant difference in the recurrence risk.

PMID:38669707 | DOI:10.3171/2024.1.JNS232508

Can J Physiol Pharmacol. 2024 Apr 26. doi: 10.1139/cjpp-2023-0447. Online ahead of print.

ABSTRACT

We aimed to determine if cheese could reduce glucose intolerance in aged rats with overt type 2 diabetes (T2D). Male Sprague-Dawley rats treated with high-fat diet and streptozotocin (STZ) exhibited hyperglycemia to elicit T2D. One week after STZ injection, low-fat (LOW) or regular-fat (REG) cheese was provided for 5 weeks and compared with T2D and low-fat diet reference (REF) groups. Food intake and weight gain were similar in all groups. Oral glucose tolerance tests revealed glucose intolerance in T2D rats that was partially ameliorated by LOW but not REG. Insulin secretion during the OGTT was impaired in T2D and REG at 10 min (p<0.05) but the iAUC was highly variable in all groups and statistical differences were not detected (p>0.05). β-cell mass and pancreatic insulin content in T2D and REG were 50% lower than REF (p<0.05) whereas LOW was not significantly different. Although isolated islets from all groups responded to glucose, the absolute amount of insulin secreted by T2D and REG was markedly reduced compared with REF while LOW islets had relatively normal secretion. In conclusion, LOW but not REG cheese enhanced β-cell recovery from HFD/STZ treatment that led to amelioration of glucose tolerance within 5 weeks.

PMID:38669698 | DOI:10.1139/cjpp-2023-0447

Neural Comput. 2024 Apr 17:1-27. doi: 10.1162/neco_a_01667. Online ahead of print.

ABSTRACT

The symmetric information bottleneck (SIB), an extension of the more familiar information bottleneck, is a dimensionality-reduction technique that simultaneously compresses two random variables to preserve information between their compressed versions. We introduce the generalized symmetric information bottleneck (GSIB), which explores different functional forms of the cost of such simultaneous reduction. We then explore the data set size requirements of such simultaneous compression. We do this by deriving bounds and root-mean-squared estimates of statistical fluctuations of the involved loss functions. We show that in typical situations, the simultaneous GSIB compression requires qualitatively less data to achieve the same errors compared to compressing variables one at a time. We suggest that this is an example of a more general principle that simultaneous compression is more data efficient than independent compression of each of the input variables.

PMID:38669695 | DOI:10.1162/neco_a_01667

Acta Orthop Belg. 2024 Mar;90(1):115-122. doi: 10.52628/90.1.12623.

ABSTRACT

The introduction of fast-track protocols decreased length of hospital stay and improved rehabilitation and outcomes in total joint arthroplasty. Despite improved clinical results published in many papers, the patient perspective of these protocols is less investigated. Purpose of this study was to explore the patient perspective of fast-track protocols in arthroplasty. A systematic search for articles of patient experiences in total hip, knee, and shoulder arthroplasty was conducted using EMBASE, MEDLINE, Cochrane, and Web-of-Science for articles published from inception to February 14, 2023. In total 12 studies were included involving 672 patients. Most patients were satisfied with short length of hospital stay and preferred rehabilitation at home with relatives for support. Various experiences were reported regarding pain and postoperative out of hospital physical therapy. Frequently, feelings of insecurity were reported because of lack of personalized information. Based on current qualitative literature, patients are satisfied with short length of hospital stay in fast-track total joint arthroplasty. Improvements in personalized information and physical therapy protocols is needed.

PMID:38669660 | DOI:10.52628/90.1.12623