Category: Statistics

J Trop Pediatr. 2021 Jul 2;67(3):fmab060. doi: 10.1093/tropej/fmab060.

ABSTRACT

BACKGROUND: With Nigeria being one of the countries with the highest neonatal mortality rate globally, identifying the risk factors associated with neonatal mortality is essential as we strive to proffer sustainable solutions.

AIM: This retrospective hospital-based survey aimed to bridge this gap by evaluating the trends and risk factors associated with neonatal mortality in a teaching hospital in Southwestern Nigeria.

METHODS: Records of newborns admitted at the special care baby unit from January 2018 to December 2019 (n = 1098) were accessed, and available data were extracted. Descriptive analysis and inferential statistics were performed at 0.05 level of significance.

RESULTS: The mortality rate was determined to be 16.9% (inborn babies- 12.9% and out-born babies- 22.3%), with 83.3% of the newborns dying within the first week. Some of the factors associated with neonatal mortality were proximity of newborns’ mothers home to the hospital [p = 0.041; Odds Ratio (OR) = 0.670; 95% Confidence Interval (CI) = 0.455-0.985], maturity of the baby at delivery (p < 0.001; OR = 0.514; CI = 0.358-0.738), place of delivery-inborn or out-born (p < 0.001; OR = 0.515; CI = 0.375-0.709), place of delivery-in a hospital or a non-hospital setting (p = 0.048; OR = 0.633; CI = 0.401-0.999), and baby’s weight (p < 0.001; CI = -0.684 to -0.411).

CONCLUSION: Findings from the study indicate that newborns delivered at home, traditional birth attendant centres or hospitals without essential healthcare facilities have a higher mortality risk. This suggests that measures to improve the accessibility of pregnant women to essential healthcare services are a prerequisite to reducing the neonatal mortality rate in Nigeria.

PMID:34363078 | DOI:10.1093/tropej/fmab060

Sci Rep. 2021 Aug 6;11(1):16014. doi: 10.1038/s41598-021-95282-2.

ABSTRACT

The ideal moment to withdraw respiratory supply of patients under Mechanical Ventilation at Intensive Care Units (ICU), is not easy to be determined for clinicians. Although the Spontaneous Breathing Trial (SBT) provides a measure of the patients’ readiness, there is still around 15-20% of predictive failure rate. This work is a proof of concept focused on adding new value to the prediction of the weaning outcome. Heart Rate Variability (HRV) and Cardiopulmonary Coupling (CPC) methods are evaluated as new complementary estimates to assess weaning readiness. The CPC is related to how the mechanisms regulating respiration and cardiac pumping are working simultaneously, and it is defined from HRV in combination with respiratory information. Three different techniques are used to estimate the CPC, including Time-Frequency Coherence, Dynamic Mutual Information and Orthogonal Subspace Projections. The cohort study includes 22 patients in pressure support ventilation, ready to undergo the SBT, analysed in the 24 h previous to the SBT. Of these, 13 had a successful weaning and 9 failed the SBT or needed reintubation -being both considered as failed weaning. Results illustrate that traditional variables such as heart rate, respiratory frequency, and the parameters derived from HRV do not differ in patients with successful or failed weaning. Results revealed that HRV parameters can vary considerably depending on the time at which they are measured. This fact could be attributed to circadian rhythms, having a strong influence on HRV values. On the contrary, significant statistical differences are found in the proposed CPC parameters when comparing the values of the two groups, and throughout the whole recordings. In addition, differences are greater at night, probably because patients with failed weaning might be experiencing more respiratory episodes, e.g. apneas during the night, which is directly related to a reduced respiratory sinus arrhythmia. Therefore, results suggest that the traditional measures could be used in combination with the proposed CPC biomarkers to improve weaning readiness.

PMID:34362950 | DOI:10.1038/s41598-021-95282-2

Sci Rep. 2021 Aug 6;11(1):16030. doi: 10.1038/s41598-021-95587-2.

ABSTRACT

In this study, a mathematical model is developed to scrutinize the transient magnetic flow of Cross nanoliquid past a stretching sheet with thermal radiation effects. Binary chemical reactions and heat source/sink effects along with convective boundary condition are also taken into the consideration. Appropriate similarity transformations are utilized to transform partial differential equations (PDE’s) into ordinary ones and then numerically tackled by shooting method. The impacts of different emerging parameters on the thermal, concentration, velocity, and micro-rotation profiles are incorporated and discussed in detail by means of graphs. Results reveal that, the escalation in magnetic parameter and Rayleigh number slowdowns the velocity and momentum of the fluid. The increase in Biot number, radiation and heat sink/source parameters upsurges the thermal boundary but, converse trend is seen for escalating Prandtl number. The density number of motile microorganisms acts as a growing function of bioconvection Lewis number and declining function of bioconvection Peclet number.

PMID:34362971 | DOI:10.1038/s41598-021-95587-2

Nat Commun. 2021 Aug 6;12(1):4754. doi: 10.1038/s41467-021-25099-0.

ABSTRACT

Chaperonins are homo- or hetero-oligomeric complexes that use ATP binding and hydrolysis to facilitate protein folding. ATP hydrolysis exhibits both positive and negative cooperativity. The mechanism by which chaperonins coordinate ATP utilization in their multiple subunits remains unclear. Here we use cryoEM to study ATP binding in the homo-oligomeric archaeal chaperonin from Methanococcus maripaludis (MmCpn), consisting of two stacked rings composed of eight identical subunits each. Using a series of image classification steps, we obtained different structural snapshots of individual chaperonins undergoing the nucleotide binding process. We identified nucleotide-bound and free states of individual subunits in each chaperonin, allowing us to determine the ATP occupancy state of each MmCpn particle. We observe distinctive tertiary and quaternary structures reflecting variations in nucleotide occupancy and subunit conformations in each chaperonin complex. Detailed analysis of the nucleotide distribution in each MmCpn complex indicates that individual ATP binding events occur in a statistically random manner for MmCpn, both within and across the rings. Our findings illustrate the power of cryoEM to characterize a biochemical property of multi-subunit ligand binding cooperativity at the individual particle level.

PMID:34362932 | DOI:10.1038/s41467-021-25099-0

Sci Rep. 2021 Aug 6;11(1):16050. doi: 10.1038/s41598-021-93921-2.

ABSTRACT

A remarkable approach for grasping the relevant statistical features of real networks with the help of random graphs is offered by hyperbolic models, centred around the idea of placing nodes in a low-dimensional hyperbolic space, and connecting node pairs with a probability depending on the hyperbolic distance. It is widely appreciated that these models can generate random graphs that are small-world, highly clustered and scale-free at the same time; thus, reproducing the most fundamental common features of real networks. In the present work, we focus on a less well-known property of the popularity-similarity optimisation model and the [Formula: see text] model from this model family, namely that the networks generated by these approaches also contain communities for a wide range of the parameters, which was certainly not an intention at the design of the models. We extracted the communities from the studied networks using well-established community finding methods such as Louvain, Infomap and label propagation. The observed high modularity values indicate that the community structure can become very pronounced under certain conditions. In addition, the modules found by the different algorithms show good consistency, implying that these are indeed relevant and apparent structural units. Since the appearance of communities is rather common in networks representing real systems as well, this feature of hyperbolic models makes them even more suitable for describing real networks than thought before.

PMID:34362942 | DOI:10.1038/s41598-021-93921-2

J Neurol Neurosurg Psychiatry. 2021 Aug 6:jnnp-2021-326386. doi: 10.1136/jnnp-2021-326386. Online ahead of print.

ABSTRACT

OBJECTIVE: To investigate longitudinal brain atrophy in patients with neuromyelitis optica spectrum disorder (NMOSD).

METHODS: We investigated the longitudinal brain atrophy rate in patients with aquaporin-4 antibody-positive NMOSD (AQP4+NMOSD) and those with multiple sclerosis (MS) in a retrospective cohort study. Brain volume was calculated with statistical parametric mapping-12.

RESULTS: We enrolled 36 patients with AQP4+NMOSD and 60 with MS. Patients with NMOSD were older and had a higher Kurtzke’s expanded disability status scale score at baseline MRI compared with those with MS. Disease duration, annual relapse rate and intervals from the last attack and from disease-modifying drugs initiation were not significantly different between the two groups. Lower normalised lesion volume and higher normalised white matter volume were found in patients with NMOSD compared with those with MS at baseline MRI. However, the annualised atrophy rate of normalised brain volume was similar between the NMOSD (median 0.47; IQR 0.75; p=0.49) and MS (median 0.46; IQR 0.84) groups. After adjustment of age and the presence of clinical relapse, no differences of the annualised atrophy rate of normalised brain volume also were found for NMOSD and MS. Patients with AQP4+NMOSD with long cord lesion showed higher annualised atrophy rate of normalised grey matter volume compared with those without long cord lesion.

CONCLUSIONS: Silent progression of brain atrophy was present in patients with AQP4+NMOSD, as shown in patients with MS, even in the clinically inactive age-matched cases. Subclinical dying back degeneration may explain the brain atrophy in patients with AQP4 +NMOSD.

PMID:34362853 | DOI:10.1136/jnnp-2021-326386

Nat Commun. 2021 Aug 6;12(1):4763. doi: 10.1038/s41467-021-25089-2.

ABSTRACT

The comparison of gene regulatory networks between diseased versus healthy individuals or between two different treatments is an important scientific problem. Here, we propose sc-compReg as a method for the comparative analysis of gene expression regulatory networks between two conditions using single cell gene expression (scRNA-seq) and single cell chromatin accessibility data (scATAC-seq). Our software, sc-compReg, can be used as a stand-alone package that provides joint clustering and embedding of the cells from both scRNA-seq and scATAC-seq, and the construction of differential regulatory networks across two conditions. We apply the method to compare the gene regulatory networks of an individual with chronic lymphocytic leukemia (CLL) versus a healthy control. The analysis reveals a tumor-specific B cell subpopulation in the CLL patient and identifies TOX2 as a potential regulator of this subpopulation.

PMID:34362918 | DOI:10.1038/s41467-021-25089-2

Clin Otolaryngol. 2021 Aug 6. doi: 10.1111/coa.13844. Online ahead of print.

ABSTRACT

OBJECTIVES: This study investigated the relationship between viral load and the incidence of olfactory and gustatory dysfunction (OD and GD), the incidence of respiratory and gastrointestinal symptoms, and the recovery of OD and GD in COVID-19 patients.

DESIGN: A Retrospective Cohort Study.

SETTING AND PARTICIPANTS: this cohort, conducted on 599 outpatients’ cases in Golestan province between February and Juan 2020.

MAIN OUTCOME MEASURES: The incidence, severity (complete or partial), and recovery time of OD and GD and their associations with cycle threshold (CT) values of SARS-CoV-2 polymerase chain reaction was assessed.

RESULTS: The mean age of patients was 38.27±13.62 years. The incidence of general symptoms included myalgia 70.1%, headache 51.8%, fever 47.7%, and dyspnea 21.4%. 41.9% of patients had gastrointestinal symptoms, including abdominal pain 26.5%, diarrhea 25.2%, nausea 20.5%, and vomiting 12.9%. 12.2% of patients had comorbidity. The trimester recovery rates of OD and GD were 93.94% and 94.74%, respectively. The mean recovery time of OD and GD was 14.56±13.37 and 13.8±3.77 days, respectively. The mean CT value in all patients was 27.45±4.55. There were significant associations between the mean of CT value with headache (P=0.04), GD (P=0.002) and OD (P=0.001).

CONCLUSIONS: The finding of this study indicates a possible association between viral load with incidence of OD and GD in COVID-19 patient’s cases and assures the recovery of OD/GD in these patients.

PMID:34358409 | DOI:10.1111/coa.13844

Dent Med Probl. 2021 Aug 6. doi: 10.17219/dmp/131022. Online ahead of print.

ABSTRACT

BACKGROUND: There are studies that examined the effect of staining on the surface properties of composite resins, using different solutions and bleaching applications. However, the effect of both staining and bleaching on the same composite specimens is an issue that needs to be investigated.

OBJECTIVES: The aim of this study was to investigate the surface microhardness, roughness and color changes (ΔE) of 2 different composite resins after staining and bleaching.

MATERIAL AND METHODS: A microhybrid and a nanohybrid composite were used in the study. One hundred and fifty specimens were prepared from each composite. The specimens were divided into 5 groups and stained for 30 days with tea, coffee, cola, red wine, or distilled water (control). Subsequently, each group was divided into 3 subgroups. Each subgroup received a 14-day application of Opalescence™ Boost, Opalescence PF or VivaStyle® Paint On Plus bleaching materials. The color as well as surface microhardness and roughness of all specimens were determined at baseline, after staining and after bleaching. Data was analyzed using the repeated-measures analysis of variance (ANOVA) and the Bonferroni method.

RESULTS: A statistically significant decrease was observed in the surface microhardness of the microhybrid composite specimens after bleaching (p < 0.05).The highest ΔE values were observed in the red wine groups for both composite resins.

CONCLUSIONS: Staining and bleaching may affect surface properties and color, depending on the type, filler and matrix content of the composite resin.

PMID:34358420 | DOI:10.17219/dmp/131022

Clin Oral Implants Res. 2021 Aug 6. doi: 10.1111/clr.13817. Online ahead of print.

ABSTRACT

OBJECTIVES: Resonance frequency analysis (RFA) is used to monitor implant stability. Its output, the Implant Stability Quotient (ISQ), supposedly correlates with insertion torque, a common measurement of primary stability. However, the reliability of RFA in condensed bone remains unclear.

MATERIAL AND METHODS: In this human cadaver study in edentulous jaws and fresh extraction sockets, implants were inserted using a split-mouth approach into condensed or untreated bone. Mean ISQ, peak insertion torque, as well as pre- and postoperative bone volume fractions (BV/TV) were assessed.

RESULTS: In edentulous jaws, insertion torque and ISQ correlated both in untreated (r = 0.63, p = 0.02) and in condensed (r = 0.82, p = < 0.01) bone. In extraction sockets, insertion torque and ISQ only correlated in untreated (r = 0.78, p < 0.01), but not in condensed bone (r = 0.15, p = 0.58). In all edentulous jaws, preoperative BV/TV correlated with insertion torque (r = 0.90, p < 0.0001), ISQ (r = 0.64, p < 0.001), and changes in BV/TV (r = -0.71, p < 0.01). In all extraction sockets, preoperative BV/TV did not correlate with either insertion torque (r = 0.33, p = 0.15), ISQ (r = 0.38, p = 0.09), or changes in BV/TV (r = -0.41, p = 0.09). Joint analysis identified preoperative BV/TV as a predictor of postoperative BV/TV (p < 0.001), insertion torque (p < 0.001), and ISQ (p < 0.001).

CONCLUSIONS: RFA is feasible for monitoring stability after late implant placement into condensed bone, but not after immediate placement into condensed fresh extraction sites.

PMID:34358360 | DOI:10.1111/clr.13817