Tag: statistics

Sci Rep. 2021 Oct 14;11(1):20418. doi: 10.1038/s41598-021-98556-x.

ABSTRACT

We present a subcritical fracture growth model, coupled with the elastic redistribution of the acting mechanical stress along rugous rupture fronts. We show the ability of this model to quantitatively reproduce the intermittent dynamics of cracks propagating along weak disordered interfaces. To this end, we assume that the fracture energy of such interfaces (in the sense of a critical energy release rate) follows a spatially correlated normal distribution. We compare various statistical features from the obtained fracture dynamics to that from cracks propagating in sintered polymethylmethacrylate (PMMA) interfaces. In previous works, it has been demonstrated that such an approach could reproduce the mean advance of fractures and their local front velocity distribution. Here, we go further by showing that the proposed model also quantitatively accounts for the complex self-affine scaling morphology of crack fronts and their temporal evolution, for the spatial and temporal correlations of the local velocity fields and for the avalanches size distribution of the intermittent growth dynamics. We thus provide new evidence that an Arrhenius-like subcritical growth is particularly suitable for the description of creeping cracks.

PMID:34650113 | DOI:10.1038/s41598-021-98556-x

Sci Rep. 2021 Oct 14;11(1):20495. doi: 10.1038/s41598-021-99368-9.

ABSTRACT

The outbreak of novel COVID-19 disease elicited a wide range of anti-contagion and economic policies like school closure, income support, contact tracing, and so forth, in the mitigation and suppression of the spread of the SARS-CoV-2 virus. However, a systematic evaluation of these policies has not been made. Here, 17 implemented policies from the Oxford COVID-19 Government Response Tracker dataset employed in 90 countries from December 31, 2019, to August 31, 2020, were analyzed. A Poisson regression model was applied to analyze the relationship between policies and daily confirmed cases using a generalized estimating equations approach. A lag is a fixed time displacement in time series data. With that, lagging (0, 3, 7, 10, and 14 days) was also considered during the analysis since the effects of policies implemented on a given day may affect the number of confirmed cases several days after implementation. The countries were divided into three groups depending on the number of waves of the pandemic observed in each country. Through subgroup analysis, we showed that with and without lagging, contact tracing and containment policies were significant for countries with two waves, while closing, economic, and health policies were significant for countries with three waves. Wave-specific analysis for each wave showed that significant health, economic, and containment policies varied across waves of the pandemic. Emergency investment in healthcare was consistently significant among the three groups of countries, while the Stringency index was significant among all waves of the pandemic. These findings may help in making informed decisions regarding whether, which, or when these policies should be intensified or lifted.

PMID:34650119 | DOI:10.1038/s41598-021-99368-9

Sci Rep. 2021 Oct 14;11(1):20422. doi: 10.1038/s41598-021-99137-8.

ABSTRACT

Pneumonia is one of the top 10 diseases by morbidity in Bhutan. This study aimed to investigate the spatial and temporal trends and risk factors of childhood pneumonia in Bhutan. A multivariable Zero-inflated Poisson regression model using a Bayesian Markov chain Monte Carlo simulation was undertaken to quantify associations of age, sex, altitude, rainfall, maximum temperature and relative humidity with monthly pneumonia incidence and to identify the underlying spatial structure of the data. Overall childhood pneumonia incidence was 143.57 and 10.01 per 1000 persons over 108 months of observation in children aged < 5 years and 5-14 years, respectively. Children < 5 years or male sex were more likely to develop pneumonia than those 5-14 years and females. Each 1 °C increase in maximum temperature was associated with a 1.3% (95% (credible interval [CrI] 1.27%, 1.4%) increase in pneumonia cases. Each 10% increase in relative humidity was associated with a 1.2% (95% CrI 1.1%, 1.4%) reduction in the incidence of pneumonia. Pneumonia decreased by 0.3% (CrI 0.26%, 0.34%) every month. There was no statistical spatial clustering after accounting for the covariates. Seasonality and spatial heterogeneity can partly be explained by the association of pneumonia risk to climatic factors including maximum temperature and relative humidity.

PMID:34650108 | DOI:10.1038/s41598-021-99137-8

Sci Rep. 2021 Oct 14;11(1):20444. doi: 10.1038/s41598-021-00092-1.

ABSTRACT

Biological reconstruction is widely used to reconstruct bone defects after resection of bone tumors in the extremities. This study aimed to identify risk factors for failure and to compare outcomes of the allograft, nonvascularized autograft, and recycled frozen autograft reconstruction after resection of primary malignant bone tumors in the extremities. A retrospective study was performed at a single center between January 1994 and December 2017. Ninety patients with primary malignant bone tumors of the extremities were treated with tumor resection and reconstruction using one of three bone graft methods: nonvascularized autograft (n = 27), allograft (n = 34), and recycled frozen autograft (n = 29). The median time for follow-up was 59.2 months (range 24-240.6 months). Overall failure of biological reconstruction occurred in 53 of 90 patients (58.9%). The allograft group had the highest complication rates (n = 21, 61.8%), followed by the recycled frozen autograft (n = 17, 58.6%) and nonvascularized autograft (n = 15, 55. 6%) groups. There was no statistically significant difference among these three groups (p = 0.89). The mean MSTS score was 22.6 ± 3.4 in the nonvascularized autograft group, 23.4 ± 2.6 in the allograft group, and 24.1 ± 3.3 in the recycled frozen autograft group. There was no significant difference among the groups (p = 0.24). After bivariate and multivariable analyses, patient age, sex, tumor location, graft length, methods, and type of reconstruction had no effects on the failure of biological reconstruction. Biological reconstruction using allograft, nonvascularized autograft, and recycled frozen autograft provide favorable functional outcomes despite high complication rates. This comparative study found no significant difference in functional outcomes or complication rates among the different types of reconstruction.

PMID:34650091 | DOI:10.1038/s41598-021-00092-1

Sci Rep. 2021 Oct 14;11(1):20496. doi: 10.1038/s41598-021-99411-9.

ABSTRACT

Cereal leaf beetle (CLB, Oulema melanopus, Coleoptera, Chrysomelidae) is a serious agricultural pest that causes considerable damages to agricultural production. The aim of this study was to characterize the bacterial communities associated with larvae and imagoes of CLB collected from various cereal host species and locations. The bacterial profile was characterized by 16S rRNA gene sequencing at the V3-V4 hypervariable region. Using taxonomy-based analysis, the bacterial community of CLB containing 16 phyla, 26 classes, 49 orders, 78 families, 94 genera, and 63 species of bacteria was identified. The abundance of Wolbachia, Rickettsia, and Lactococcus genus was significantly higher in CLB imagoes than in larvae. Statistical analysis confirmed that the bacterial community of the larvae is more diverse in comparison to imagoes and that insects collected from spring barley and wheat are characterized by a much higher biodiversity level of bacterial genera and species than insects collected from other cereals. Obtained results indicated that the developmental stage, the host plant, and the insect’s sampling location affected the CLB’s microbiome. Additionally, the CLB core microbiome was determined. It consists of 2 genera (Wolbachia and Rickettsia) shared by at least 90% tested CLB insects, regardless of the variables analysed.

PMID:34650106 | DOI:10.1038/s41598-021-99411-9

Blood Coagul Fibrinolysis. 2021 Oct 1;32(7):504-512. doi: 10.1097/MBC.0000000000001074.

ABSTRACT

Mannose-binding lectin-associated serine protease-1 (MASP-1) is known to interact with complement and coagulation pathways. Recently it was reported that MASP-1 interacts with the fibrinolytic system but details remain unclear. The objective of the study is to find MASP-1 substrates that participate in the fibrinolytic system. Commercially available fibrinogen might contain some impurities. Fibrinogen was treated with MASP-1 followed by analysis on SDS-PAGE and the obtained cleaved fragments were identified by matrix-assisted laser desorption/ionization-time of flight/time of flight. Functional analysis of identified substrate was confirmed by fluorogenic and turbidimetric assay. Statistical analysis was done by using the Student t test. This study reports that plasminogen and plasma fibronectin are two hitherto unknown substrates of MASP-1. Conversion of plasminogen to plasmin like molecule by MASP-1 was confirmed by cleavage of plasmin specific substrate and digestion of fibrin clot. The role of MASP-1 in clot dissolution was confirmed by turbidity assay. Our study shows that MASP-1 selects plasminogen over fibrinogen to be a preferable substrate. MASP-1 promotes the fibrinolytic activity by the generation of plasmin like molecule from plasminogen and further destabilizes the clot by digestion of plasma fibronectin.

PMID:34650023 | DOI:10.1097/MBC.0000000000001074

Sci Rep. 2021 Oct 14;11(1):20429. doi: 10.1038/s41598-021-00004-3.

ABSTRACT

Fractional calculus characterizes a function at those points, where classical calculus failed. In the current study, we explored the fractional behavior of the stagnation point flow of hybrid nano liquid consisting of TiO₂ and Ag nanoparticles across a stretching sheet. Silver Ag and Titanium dioxide TiO₂ nanocomposites are one of the most significant and fascinating nanocomposites perform an important role in nanobiotechnology, especially in nanomedicine and for cancer cell therapy since these metal nanoparticles are thought to improve photocatalytic operation. The fluid movement over a stretching layer is subjected to electric and magnetic fields. The problem has been formulated in the form of the system of PDEs, which are reduced to the system of fractional-order ODEs by implementing the fractional similarity framework. The obtained fractional order differential equations are further solved via fractional code FDE-12 based on Caputo derivative. It has been perceived that the drifting velocity generated by the electric field E significantly improves the velocity and heat transition rate of blood. The fractional model is more generalized and applicable than the classical one.

PMID:34650086 | DOI:10.1038/s41598-021-00004-3

Eur Endod J. 2021 Aug;6(2):221-225. doi: 10.14744/eej.2021.30602.

ABSTRACT

OBJECTIVE: To compare the amount of apically extruded bacteria between hand-filed preparations, rotary and reciprocation glide path preparations in curved canals of extracted teeth infected with Enterococcus faecalis.

METHODS: Forty mandibular first molar teeth were decoronated, fitted into rubber stoppers and fixed onto glass vials. The mesiobuccal canals from mandibular first molar teeth were infected with Enterococcus faecalis, then randomly assigned to one of five groups for glide path preparation: manual stainless-steel file (K-files), rotary file (One G), reciprocating file (WaveOne Gold Glider) and two control groups. After glide path preparation, 0.01 mL of saline was taken from the experimental vials. The solution was plated on tryptic soy agar and colonies of bacteria were counted as colony-forming units. The results were analysed statistically using Kruskal-Wallis and post hoc Mann-Whitney U tests.

RESULTS: The manual K-file group was associated with significantly more bacteria extrusion compared to the rotary and reciprocating groups (P<0.05). However, no significant difference occurred between rotary and reciprocation instruments.

CONCLUSION: All instrumentation techniques resulted in a measurable amount of apical extrusion of bacteria. Manual K-files extruded the highest quantity of bacteria compared to One G rotary file and WaveOne Gold Glider reciprocation file during glide path preparation.

PMID:34650017 | DOI:10.14744/eej.2021.30602

Blood Coagul Fibrinolysis. 2021 Oct 1;32(7):496-503. doi: 10.1097/MBC.0000000000001088.

ABSTRACT

This study aimed to detect the defects of the current methods used to monitor unfractionated heparin (UFH) anticoagulant effect and find possible assistive parameters for activated partial thromboplastin time (aPTT) test to improve treatment performance. The required information was gathered from patients’ case records, treatment charts and laboratory reports. Kendall’s tau correlation coefficient was calculated for analysing the relationship between variables. The partial least squares (PLS) and the stepwise multiple regression were operated, and the area under the receiver operating characteristic curve (AUC) and the r-squared (r2) were used to show the analytical ability of the models, respectively. Overall, 102 UFH-receiving ischemic heart disease patients participated in this study. The aPTT value varied from 30 to 95 s (mean ± SD = 44 ± 14). Therapeutic aPTT values were observed in 15% of hospitalization days. The aPTT value showed statistically significant correlations with mean UFH infusion (U/kg/h), age, prothrombin time (PT), smoking, international normalized ratio, haemoglobin (Hgb) and blood triglyceride level. Triglyceride level and PT were efficacious predictors of aPTT value (P < 0.001, r2 = 0.336). Moreover, blood urea nitrogen (BUN) and blood creatinine (Cr) levels were the best predictors for mortality. The mean BUN/Cr ratio was 18 ± 5 and 25 ± 12 in nonexpired and expired subjects, respectively. If calibrated institution-specific therapeutic aPTT ranges and updated weight-based UFH nomograms get employed, aPTT test, along with the BUN/Cr ratio and Hgb level, as assistive parameters for predicting haemorrhagic incidents, would be near ideal monitoring method in UFH-receiving patients.

PMID:34650022 | DOI:10.1097/MBC.0000000000001088

Eur Endod J. 2021 Aug;6(2):189-196. doi: 10.14744/eej.2021.66375.

ABSTRACT

OBJECTIVE: To assess and quantify coronal tooth discolouration by ProRoot MTA, Biodentine and MTA repair HP as pulpotomy agents and to identify colour stability of these materials in presence of blood contamination.

METHODS: 120 human premolar teeth were used in the study. The teeth were sectioned horizontally 1 mm apical to the cementoenamel junction. A retrograde cavity extending within 2 mm of the incisal edge was prepared. The specimens were randomly distributed as; Control: Group 1, ProRoot MTA: Group 2, Biodentine: Group 3 and MTA repair HP: Group 4. The groups werefurther subdivided on basis of exposure to saline (subgroup A) or blood (subgroup B). The access was sealed with light cured Glass ionomer cemet and the specimens were stored in artificial saliva at 37°C. The Colour change was evaluated with a spectrophotometer at: day 0 (T0), day 1 (T1), day 7 (T7), 1 month (T30), 2 months (T60), and 6 months (T180). The colour measurements were recorded using the Commission Internationale de l’Eclairage L*a*b* value.

RESULTS: For all groups, there was a sharp increase in L* parameter at T1. At 6 months, Group 1B (Control + blood) showed maximum decrease in luminosity followed by Group 2A (ProRoot + saline) > Group 4B (MTA repair HP + blood) > Group 2B (ProRoot + blood). Group 3A (Biodentine + saline) showed the least amount of decrease in luminosity followed by Group 4A (MTA repair HP + saline) and Group 3B (Biodentine + blood). No significant difference was found in ∆E change between any of the groups from baseline to 180 days (P>0.05).

CONCLUSION: Relative to L* parameter, it was possible to observe a statistically significant decrease in luminosity in the Group1B (Control + blood) followed by ProRoot MTA (Group 2A and 2B) and MTA repair HP (Group 4A and 4B). Biodentine (Group 3A and 3B) showed least tooth discolouration in terms of L* parameter.

PMID:34650014 | DOI:10.14744/eej.2021.66375