Category: Statistics

Micron. 2021 Aug 8;150:103135. doi: 10.1016/j.micron.2021.103135. Online ahead of print.

ABSTRACT

A detailed numerical study of the formation of metallic silver thin films ranged from 8 up to 50 nm on thickness is presented. The topography of these films was imaged by Atomic Force Microscopy, and starting from these images, some surface parameters were obtained. We characterized the root mean square roughness evolution by a simple power-law model with a coefficient α=0.74±0.01 consistent with the theoretical results of Family and Vicsek (1985), Family (1990). Additionally, we considered different models to describe the distributions of the grains’ heights and sizes, and analyzed them via Bayesian statistics and a Markov Chain Monte Carlo numerical method. This Bayesian analysis has been significantly helpful in this work for allowing the study of the models that represent our data best and considering the experimental errors as instrumental data. The results of this analysis suggest an individual grains’ growth followed by a collapse between neighboring grains.

PMID:34390976 | DOI:10.1016/j.micron.2021.103135

Ecotoxicol Environ Saf. 2021 Aug 11;223:112604. doi: 10.1016/j.ecoenv.2021.112604. Online ahead of print.

ABSTRACT

The demand for the effective traceability of hazardous chemicals is crucial for preventing and controlling chemical spills and other accidents involving hazardous chemicals. The aim of the study was to investigate the correlation between the geographical location of ethanol-producing industrial sites and the carbon, hydrogen, and oxygen stable isotope ratios of the Chinese-manufactured ethanol using statistical classification analysis to enable the traceability of the ethanol. The isotopic data of 54 ethanol samples obtained from 18 different ethanol manufacturing plants in China between 2019 and 2020. The results of the statistical analysis demonstrated that the δ¹⁸O values of the ethanol positively correlated with latitudes of the production plants but negatively correlated with the δ¹³C values of the ethanol. A small number of samples derived from sites that were geographically close to each other could not be visually distinguished by PCA and HCA. However, by applying and comparing the results of classification by LDA, K-NN and Ensemble, an optimal classification model was obtained. Upon application of these models, 96.3% of the ethanol samples were correctly classified based on their geographical origin, indicating that the combination of isotopic ratios and latitude data is practical and effective for measuring the traceability of ethanol.

PMID:34390986 | DOI:10.1016/j.ecoenv.2021.112604

Drug Alcohol Depend. 2021 Jul 28;227:108943. doi: 10.1016/j.drugalcdep.2021.108943. Online ahead of print.

ABSTRACT

BACKGROUND: Continuing care following inpatient addiction treatment is an important component in the continuum of clinical services. Mutual help, including 12-step groups like Alcoholics Anonymous, is often recommended as a form of continuing care. However, the effectiveness of 12-step groups is difficult to establish using observational studies due to the risks of selection bias (or confounding).

OBJECTIVE: To address this limitation, we used both conventional and machine learning-based propensity score (PS) methods to examine the effectiveness of 12-step group involvement following inpatient treatment on substance use over a 12-month period.

METHODS: Using data from the Recovery Journey Project – a longitudinal, observational study – we followed an inpatient sample over 12-months post-treatment to assess the effect of 12-step involvement on substance use at 12-months (n = 254). Specifically, PS models were constructed based on 34 unbalanced confounders and four PS-based methods were applied: matching, inverse probability weighting (IPW), doubly robust (DR) with matching, and DR with IPW.

RESULTS: Each PS-based method minimized the potential of confounding from unbalanced variables and demonstrated a significant effect (p < 0.001) between high 12-step involvement (i.e., defined as having a home group; having a sponsor; attending at least one meeting per week; and, being involved in service work) and a reduced likelihood of using substances over the 12-month period (odds ratios 0.11 to 0.32).

CONCLUSIONS: PS-based methods effectively reduced potential confounding influences and provided robust evidence of a significant effect. Nonetheless, results should be considered in light of the relatively high attrition rate, potentially limiting their generalizability.

PMID:34390964 | DOI:10.1016/j.drugalcdep.2021.108943

Int J Drug Policy. 2021 Aug 11;95:103398. doi: 10.1016/j.drugpo.2021.103398. Online ahead of print.

ABSTRACT

BACKGROUND: Individuals who initiate injection drug use often receive assistance from an injection-knowledgeable peer. Persons who assist peers in injection initiation events often inject frequently, which heightens overdose risk. As such, overdose and injection initiation events may be correlated. To explore a potential relationship, we assessed temporal associations between experiencing a non-fatal overdose and assisting others in initiating injection drug use among persons who inject drugs in two North American cities – Vancouver, Canada and Tijuana, Mexico.

METHODS: From 2014 to 2018, this retrospective cohort study included people who inject drugs from Vancouver (n=1332) and Tijuana (n=666) who completed a baseline and six-month follow-up interview. Within each site, we assessed bidirectional temporal associations using two separate multivariable logistic regression models: for model 1, recent provision of injection initiation assistance (at six months) was the outcome and recent overdose (at baseline) was the exposure; for model 2, recent overdose (at six months) was the outcome and recent provision of injection initiation assistance (at baseline) was the exposure. Both models adjusted for potential confounders.

RESULTS: Vancouver-based participants reporting overdose at baseline had 163% greater odds of reporting provision of injection initiation assistance at follow-up (adjusted Odds Ratio [aOR] 2.63; 95% Confidence Interval [CI] 1.41-4.90); while participants reporting provision of injection initiation assistance at baseline had 89% greater odds of reporting a non-fatal overdose at follow-up (aOR 1.89; 95% CI 1.00-3.57). Among Tijuana-based participants, we did not observe a statistically significant association in either direction.

CONCLUSION: Findings in Vancouver suggest that injection initiation assistance and overdose are bidirectionally-associated phenomena. The present findings highlight the need for interventions that ensure that persons who provide injection initiation assistance are given overdose prevention support, both for themselves and for those they assist to initiate injection drug use. While our Tijuana-based results did not suggest a bidirectional relationship, preventative approaches should nonetheless be undertaken.

PMID:34390966 | DOI:10.1016/j.drugpo.2021.103398

Comput Methods Programs Biomed. 2021 Jul 29;209:106322. doi: 10.1016/j.cmpb.2021.106322. Online ahead of print.

ABSTRACT

BACKGROUND AND OBJECTIVE: We present and analyze a nonstandard numerical method to solve an epidemic model with memory that describes the propagation of Ebola-type diseases. The epidemiological system contemplates the presence of sub-populations of susceptible, exposed, infected and recovered individuals, along with nonlinear interactions between the members of those sub-populations. The system possesses disease-free and endemic equilibrium points, whose stability is studied rigorously.

METHODS: To solve the epidemic model with memory, a nonstandard approach based on Grünwald-Letnikov differences is used to discretize the problem. The discretization is conveniently carried out in order to produce a fully explicit and non-singular scheme. The discrete problem is thus well defined for any set of non-negative initial conditions.

RESULTS: The existence and uniqueness of the solutions of the discrete problem for non-negative initial data is thoroughly proved. Moreover, the positivity and the boundedness of the approximations is also theoretically elucidated. Some simulations confirm the validity of these theoretical results. Moreover, the simulations prove that the computational model is capable of preserving the equilibria of the system (both the disease-free and the endemic equilibria) as well as the stability of those points.

CONCLUSIONS: Both theoretical and numerical results establish that the computational method proposed in this work is capable of preserving distinctive features of an epidemiological model with memory for the propagation of Ebola-type diseases. Among the main characteristics of the numerical integrator, the existence and the uniqueness of solutions, the preservation of both positivity and boundedness, the preservation of the equilibrium points and their stabilities as well as the easiness to implement it computationally are the most important features of the approach proposed in this manuscript.

PMID:34390936 | DOI:10.1016/j.cmpb.2021.106322

J Psychosom Res. 2021 Jul 31;149:110591. doi: 10.1016/j.jpsychores.2021.110591. Online ahead of print.

ABSTRACT

BACKGROUND: Depression is a major cause of the global disease burden and globally affects 350-400 million persons making it the largest contributor to years lived with disability. Among of patients with chronic physical illnesses like tuberculosis, depression affects up to 25-33% of individuals. There are limited studies on the comorbidity of depressive illness and tuberculosis in the Ugandan setting. Our aim was to determine the prevalence and factors associated with depressive illness in patients with tuberculosis in Mulago Hospital, Uganda.

METHODS: This was a cross sectional study involving 308 consecutively sampled participants aged 18 years and above diagnosed with tuberculosis attending the tuberculosis clinic in Mulago Hospital, Uganda. Consecutive sampling was done for a sample size of 308 participants. Participants had the following instruments administered to them; the Socio-demographic questionnaire, the Mini Neuropsychiatric Interview (MINI) to diagnose depressive illness and the Patient Health Questionnaire- 9 to rate the severity of depression. Data was entered using Epi-Data. Descriptive, bivariate and multivariate analyses were done with the Statistical Package for Social Sciences (SPSS).

RESULTS: the prevalence of depressive illness was 23.7% (95% confidence interval 19.3-28.9). Depressive illness was independently associated with low education level (AOR = 0.39, 95%CI = 0.21-0.72, p = 0.003), being in the intensive phase of TB treatment (AOR = 2.34, 95%CI = (1.27-4.33), p = 0.007) and family history of depressive illness (AOR = 5.42, 95%CI = 2.02-14.54, p = 0.001). On the PHQ, 60.3% had moderate to severe depression.

CONCLUSION: Depressive illnesses should be screened and managed among patients with TB.

RECOMMENDATION: Depression should be routinely screened and managed among patients with Tuberculosis.

PMID:34390942 | DOI:10.1016/j.jpsychores.2021.110591

Andrology. 2021 Aug 14. doi: 10.1111/andr.13094. Online ahead of print.

ABSTRACT

BACKGROUND: Patients with cancer are treated with chemotherapeutics that cause adverse effects, including erectile dysfunction (ED).

OBJECTIVES: We investigated erectile function in rats after the administration of anticancer agents based on data retrieved through mining of the US Food and Drug Administration (FDA) Adverse Event Reporting System (AERS) database.

MATERIALS AND METHODS: The statistical signal strength for the association between anticancer drugs and ED was calculated using the reporting odds ratio (ROR). A drug-event combination was detected when the lower limit of the 95% confidence interval (CI) of the ROR exceeded 1.00. Rats were administered anticancer agents detected in the FDA AERS analysis. Erectile function was assessed using intracavernous pressure (ICP) and mean arterial pressure (MAP) analysis after electrical stimulation of the cavernous nerve. Statistical significance was determined using Welch’s t-test or two-way ANOVA.

RESULTS: Melphalan (L-PAM; ROR = 4.72, 95% CI = 2.78-8.00), vincristine (VCR; ROR = 2.47, 95% CI = 1.54-3.97), docetaxel (DTX; ROR = 2.25, 95% CI = 1.28-3.95), methotrexate (MTX; ROR = 1.96, 95% CI = 1.39-2.75), and doxorubicin (DOX; ROR = 1.82, 95% CI = 1.07-3.19) enhanced ED risk. L-PAM and MTX decreased the ICP/MAP ratio 1 week after administration. VCR and DOX decreased erectile function 4 weeks after administration. DTX decreased erectile function at all assessed time points.

DISCUSSION AND CONCLUSION: Certain anticancer agents should be considered risk factors for ED. Our results provide possible treatment strategies for maintaining erectile function in cancer survivors, including careful erectile function monitoring after treatment. This article is protected by copyright. All rights reserved.

PMID:34390622 | DOI:10.1111/andr.13094

Undersea Hyperb Med. 2021 Third-Quarter;48(3):209-219.

ABSTRACT

Eustachian tube dysfunction (ETD) and middle ear barotrauma (MEB) are common reported complications during hyperbaric oxygen treatment. Our Phase I study data was the first to demonstrate a statistically significant decrease in the occurrence of symptomatic ETD and MEB. The Phase I Trial suggested the total time interval and rate (slope) of compression (ROC) may be a determining factor in ETD and MEB. This Phase II study investigates an optimal rate of compression to reduce ETD and MEB when considering each multiplace treatment (with multiple patients) as the unit of observation as a group, rather than for each individual patient. Data were collected prospectively on 1,244 group patient-treatment exposures, collectively including 5,072 individual patient-treatment/exposures. We randomly assigned patient-treatment group exposures to four different time interval and rate (slope) of compression. These compression rates and slopes were identical to those used in the Phase I trial. All patients experiencing symptoms of MEB requiring compression stops were evaluated post treatment for the presence of ETD and MEB using the O’Neill Grading System (OGS) for ETD. Data were analyzed using the IBM-SPSS statistical software program. A statistically significant decrease in the number of compression holds was observed in the 15-minute compression schedule, correlating to the results observed in the Phase I trial. The 15-minute linear compression profile continues to demonstrate the decreased need for patient symptomatic compression stops (as in the Phase I trial) using a USN TT9 during elective hyperbaric oxygen treatments in a Class A multiplace hyperbaric chamber. Trial Registration: ClinicalTrials.gov Identifier: NCT04776967.

PMID:34390625

Drug Metab Pers Ther. 2021 Aug 13. doi: 10.1515/dmdi-2021-0118. Online ahead of print.

ABSTRACT

OBJECTIVES: The aim of this study is to assess micro-RNAs miR-142 and miR-39 as potential biomarkers for drug-monitoring of rivaroxaban among elderly patients with atrial fibrillation.

METHODS: The study involved 57 patients with median (ME) age 87 years [80-94 years old] with nonvalvular atrial fibrillation admitted to a multidisciplinary hospital in Moscow. High-performance liquid chromatography with mass-spectrometry detection (HPLC-MS) was carried out to measure rivaroxaban concentrations. Carriership of CYP3A4 and ABCB1 was detected. MiRNA expression levels were measured. The activity of CYP3A4 isoenzyme was measured as the ratio of the concentrations of 6β-hydroxycortisol and cortisol.

RESULTS: The miR-142 expression levels of patients with CC allelic variant polymorphism ABCB1 3435 C>T (rs1045642) were significantly higher compared to CT and TT variants 31.69 ± 1.60 vs. 34.06 ± 1.66 vs. 33.16 ± 1.77 (p=0.021). Carriers of TT allelic variant polymorphism ABCB1 rs4148738 had a higher concentration of the 6-beta-hydroxycortisol in urine compared to CC and CT variants 3,467.35 ± 1,055.53 vs. 3,453.52 ± 1,516.89 vs. 2,593.30 ± 1,172.52 (p=0.029). As for CYP3A4*22, the carriers of CC allelic variant had higher prothrombin time 14.10 ± 2.17 vs. 11.87 ± 0.60 and INR 1.31 ± 0.20 vs. 1.1 ± 0.06 but lower Quick’s value 74.52 ± 16.84 vs. 97.55 ± 10.54 (p=0.059). A positive correlation between the Ct miR-142 and the aPTT p=0.019 was noted. Also miR-142 has a correlation with Quick’s value p=0.095. There is no statistically significant connection between miR-142 and miR-39 expression levels and the plasma concentration of rivaroxaban (b coefficient=-2.055, SE 3.952, p=0.605 and b coefficient=1.546, SE 9.887, p=0.876 in the linear regression model respectively).

CONCLUSIONS: This study has assessed new potential biomarkers for rivaroxaban therapeutic drug monitoring: miR-142 and miR-39.

PMID:34390638 | DOI:10.1515/dmdi-2021-0118

Biometrics. 2021 Aug 14. doi: 10.1111/biom.13544. Online ahead of print.

ABSTRACT

In cancer research, supervised heterogeneity analysis has important implications. Such analysis has been traditionally based on clinical/demographic/molecular variables. Recently, histopathological imaging features, which are generated as a byproduct of biopsy, have been shown as effective for modeling cancer outcomes, and a handful of supervised heterogeneity analysis has been conducted based on such features. There are two types of histopathological imaging features, which are extracted based on specific biological knowledge and using automated imaging processing software, respectively. Using both types of histopathological imaging features, our goal is to conduct the first supervised cancer heterogeneity analysis that satisfies a hierarchical structure. That is, the first type of imaging features defines a rough structure, and the second type defines a nested and more refined structure. A penalization approach is developed, which has been motivated by but differs significantly from penalized fusion and sparse group penalization. It has satisfactory statistical and numerical properties. In the analysis of lung adenocarcinoma data, it identifies a heterogeneity structure significantly different from the alternatives and has satisfactory prediction and stability performance. This article is protected by copyright. All rights reserved.

PMID:34390584 | DOI:10.1111/biom.13544