Tag: statistics

J Mech Behav Biomed Mater. 2021 Nov 29;126:105001. doi: 10.1016/j.jmbbm.2021.105001. Online ahead of print.

ABSTRACT

The effect of bleach treatments on the morphology and mechanical properties of hair surfaces was measured at the nanometer scale using atomic force microscopy. We used an ultrahigh-precision relocation technique to observe the variations in these properties at precise locations on hair surfaces in their virgin state and then after each of the two bleach treatments, to rule out position-dependent fluctuations. We demonstrate that statistically significant variations in roughness and Young’s modulus are observed as a result of exposure to bleach, which is known to disrupt the disulfide linkage network throughout the fiber. The rate at which surface roughness changes increased with the number of treatments, with very little effect seen after 10 min, and an increase of up to 65% was observed after a further 10 min. The Young’s modulus decreased by up to 40% after each treatment. We also investigate micropores and show that they are subsurface, but revealed through bleaching, and oriented along the direction of the hair shaft with a characteristic aspect ratio. This work demonstrates the profound effect bleaching has on the molecular structure of hair, which manifests as changes in morphology and stiffness, and this should be taken into account in the formulation of future hair-care products.

PMID:34922297 | DOI:10.1016/j.jmbbm.2021.105001

Forensic Sci Int. 2021 Nov 29;331:111126. doi: 10.1016/j.forsciint.2021.111126. Online ahead of print.

ABSTRACT

Shoe prints are commonly found at the scene of a crime and can sometimes help link a suspect to the scene. Because prints tend to be partially observed or smudgy, comparing crime scene prints with reference images from a putative shoe can be challenging. Footwear examiners rely on guidelines such as those published by SWGTREAD [1] to visually assess the similarity between two or more footwear impressions, one reason being that reliable, quantitative methods have yet to be validated for use in real cases. To help in the development of such methods, we created a study dataset of images of outsole impressions that shared class characteristics and degree of wear and that were subject to a specific type of degradation. We also propose a method to quantify the similarity between two outsole images that extends the capabilities of MC-COMP [2]. The proposed method is composed of three steps; (1) extracting image descriptors, (2) aligning images using the maximum clique, (3) calculating similarity values using two different classifiers; (a) degree of overlap between the two images, and (b) a score produced by a random forest. To explore the performance of the algorithm we propose, we compared degraded, crime scene-like images to high-quality reference images produced by the same or by different shoes. Even though comparisons involved matches or very close non-matches, and one of the images was blurry, the algorithm shows good source classification performance.

PMID:34922283 | DOI:10.1016/j.forsciint.2021.111126

Clin Neurol Neurosurg. 2021 Dec 14;212:107090. doi: 10.1016/j.clineuro.2021.107090. Online ahead of print.

ABSTRACT

STUDY DESIGN: Retrospective Review INTRODUCTION/OBJECTIVE: The aim of this study is to utilize a national database to identify how age affects patient outcomes following anterior lumbar interbody fusion (ALIF). There are no established age guidelines for the geriatric population within the spine specialty, which makes patient selection challenging. Furthermore, there are conflicting studies for the risks of performing spine surgeries in the elderly.

METHODS: A retrospective review of the Mariner Claims Database was conducted on patients who underwent a single level ALIF (CPT 22558) between 2010 and 2018. Patients were separated into three groups by age: 50-64, 65-74, and 75-84 and matched with respect to gender, smoking, and comorbidity burden. Multivariable logistic regression was used to determine the independent effect of outpatient surgery on the postoperative outcomes after adjusting for demographic factors and pertinent comorbidities. Statistical significance was set at p < 0.05.

RESULTS: The study identified 8459 matched patients (3350 50-64; 3350 65-74; and 1759 75-84). Compared with patients aged 50-64, patients aged 65-74 and 75-84 had significantly increased risks of pneumonia (65-74: OR 1.53, 95% CI 1.06-2.24, p = 0.025; 75-84: OR 1.62, 95% CI 1.07-2.42, p = 0.022), sepsis (65-74: OR 2.20, 95% CI 1.36-3.76, p = 0.002; 75-84: OR 2.42, 95% CI 1.43-4.13, p = 0.001), and major complications (65-74: OR 1.35, 95% CI 1.05-1.74, p = 0.021; 75-84: OR 1.48, 95% CI 1.11-1.95, p = 0.006) (Table 2). There were no significant differences between patients aged 65-74 and 75-84 for risks of postoperative pneumonia, sepsis, and major complications (p > 0.05). There were no differences between any groups in terms of long-term outcomes such as pseudoarthrosis, implant related complications, or reoperation (p > 0.05) (Table 3).

DISCUSSION/CONCLUSION: The study showed that those older than 65 had a significant increase in risk of pneumonia, sepsis, and major complications following ALIF. In the two cohorts above the age of 65 (65-74 and 75-84) there was no significant differences in postoperative outcomes.

LEVEL OF EVIDENCE: 3.

PMID:34922291 | DOI:10.1016/j.clineuro.2021.107090

J Surg Res. 2021 Dec 15;272:9-16. doi: 10.1016/j.jss.2021.11.007. Online ahead of print.

ABSTRACT

BACKGROUND: While many factors influence medical student career choice, interactions with attending and resident physicians during clinical rotations are particularly important. To evaluate the influence of attending and resident physicians on medical students’ career choices, particularly for those pursuing surgical careers, we quantified their respective influence in the context of other known influences.

METHODS: Rising fourth-year medical students and new graduates were given an IRB-exempt, 14-item online survey. Descriptive statistics were performed on the demographic information. Chi-square analysis was used, as were Kruskal-Wallis and Mann-Whitney analyses on the Likert responses (α = 0.05).

RESULTS: Survey response was 24%. Students pursuing general surgery rated residents greater than or equal to attendings on 7 of 8 key mentoring characteristics. Of students choosing a different specialty than the one they intended to pursue upon entering medical school, the influence of residents was cited by 100% of the students pursuing general surgery, compared to 59% of the entire cohort. Identification of a role model and perceived personality fit were significantly more important than other factors (P < 0.0001). Students pursuing general surgery rated the importance of identifying a role model and perceived personality fit greater than their peers.

CONCLUSIONS: Residents have greater influences on medical students’ career choice compared to attendings. Students pursuing a surgical specialty, particularly general surgery, considered the influence of role models and perceived personality fit to be the most important factors in their specialty decision. These findings provide valuable insights to improve student experiences and career recruitment in surgical specialties, particularly general surgery.

PMID:34922268 | DOI:10.1016/j.jss.2021.11.007

Cancer Genet. 2021 Dec 6;260-261:41-45. doi: 10.1016/j.cancergen.2021.12.001. Online ahead of print.

ABSTRACT

Promoter hypermethylation have been reported to play a key role in bladder cancer development and progression. The aim of this study is to evaluate the methylation status of hTERT, TWIST1, VIM and NID2 genes in bladder cancer. The methylation status was evaluated using the Methylation-Specific PCR (MSP) approach on 70 tumour biopsies from Moroccan bladder cancer patients. Overall, methylation frequencies of hTERT, TWIST1, VIM and NID2 genes, were 90%, 85.71%, 67.14% and 67.14%, respectively. Hypermethylation of all studied genes was found in all pathological grades and stages of bladder cancer. Nevertheless, statistical analysis showed no significant association between promoter methylation of hTERT, TWIST1, VIM and NID2 genes and tumours stage/grade (p value >0.05). Moreover, we have investigated the association between the methylation pattern of selected genes and the treatment outcome in a sub-group of non-muscle-invasive bladder cancer cases (52/70). Hypermethylation of hTERT, TWIST1, VIM and NID2 was detected in 83.34%; 66.67%; 83.34% and 58.34% of recurrent cases, respectively, and in 80%; 80%; 80% and 60% of progressive cases, respectively. Statistical analysis highlighted a significant association between TWIST1 hypermethylation and tumour recurrence (p = 0.041<0.05). Our results indicate that hypermethylation of hTERT, TWIST1, VIM and NID2 genes is a frequent epigenetic event in bladder cancer and could be a promising therapeutic target to prevent bladder cancer progression and metastasis.

PMID:34922269 | DOI:10.1016/j.cancergen.2021.12.001

J Surg Res. 2021 Dec 15;272:26-36. doi: 10.1016/j.jss.2021.11.006. Online ahead of print.

ABSTRACT

BACKGROUND: Thermography is a diagnostic method based on the ability to record infrared radiation emitted by the skin and is unique in its ability to accurately show physiological and/or pathological cutaneous temperature changes in a non-invasive way. This method can be used to indirectly assess changes or impairments in cutaneous perfusion. Significant technological advancements have allowed thermography to be more commonly utilized by clinicians, yet a basic consensus of patient characteristics that may affect temperature recordings is not established.

MATERIALS AND METHODS: We evaluated cutaneous temperature in a cohort of outpatients to understand what factors, including tobacco use and other high-risk characteristics, contribute to cutaneous tissue perfusion as measured by thermography. Participants were prospectively enrolled if they were a combustible cigarette smoker, an electronic cigarette (e-cigarette) user, or a never smoker. Standardized thermographic images of the subject’s facial profiles, forearms, and calves were taken and demographic characteristics, medical comorbidities, and tobacco product use were assessed. These variables were statistically tested for associations with temperature at each anatomic site.

RESULTS: We found that gender had a significant effect on thermographic temperature that differed by anatomic site, and we found a lack of significant difference in thermographic temperature by race. Our regression analysis did not support significant differences in thermographic temperatures across smoking groups, while there was a trend for decreased perfusion in smokers relative to non-smokers and e-cigarette users relative to non-smokers.

CONCLUSION: Thermographic imaging is a useful tool for clinical and research use with consideration of sex and other perfusion-affecting characteristics.

PMID:34922267 | DOI:10.1016/j.jss.2021.11.006

Am J Otolaryngol. 2021 Dec 14;43(2):103320. doi: 10.1016/j.amjoto.2021.103320. Online ahead of print.

ABSTRACT

INTRODUCTION: COVID-19 may have many nonspecific symptoms, such as hearing loss, tinnitus and dizziness. This study aims to investigate the effects of SARS-CoV-2 on the hearing thresholds of patients with COVID-19.

METHODS: A total of 20 patients aged 20-55 years who were diagnosed with COVID-19 were included in this study. The relationship between the pure-tone thresholds of patients before and after COVID-19 was evaluated.

RESULTS: There was no statistically significant difference between bone conduction pure-tone thresholds in all frequencies before and after COVID-19.

CONCLUSION: SARS-CoV-2 has no effects on the hearing thresholds in patients with non-hospitalized mild COVID-19 disease. Further studies are needed to investigate the possible effects of SARS-CoV-2 on the auditory system.

PMID:34922259 | DOI:10.1016/j.amjoto.2021.103320

Eur J Cancer. 2021 Dec 15;161:55-63. doi: 10.1016/j.ejca.2021.11.003. Online ahead of print.

ABSTRACT

AIM: Early-stage epithelial ovarian cancer (eEOC) patients have a generally favorable prognosis but unpredictable recurrence. Accurate prediction of risk of relapse is still a major concern, essentially to avoid overtreatment. Our robust tissue-based miRNA signature named MiROvaR, predicting early EOC recurrence in mostly advanced-stage EOC patients, is here challenged in an independent cohort to extend its classifying ability in the early-stage EOC setting.

METHODS: We retrospectively selected patients who underwent comprehensive surgical staging at our institution including stages from IA to IIB. miRNA expression profile was analysed in 89 cases and MiROvaR algorithm was applied using the previously validated cut-off for patients’ classification. The primary endpoint was progression-free survival (PFS) at 5 years. Complete follow-up time (median = 112 months) was also considered as secondary analysis.

RESULTS: MiROvaR was assessable on 87 cases (19 events of disease progression) and classified 68 (78%) low-risk and 19 (22%) high-risk patients. Recurrence rate at primary end-point was 39% for high-risk patients as compared to 9.5% for low-risk ones. Accordingly, their Kaplan-Meier PFS curves were significantly different at both primary and secondary analysis (p = 0.0006 and p = 0.03, respectively). While none of the prominent clinical variables had prognostic relevance, MiROvaR significantly predicted disease recurrence at the 5-year assessment (primary endpoint analysis; HR:5.43, 95%CI:1.82-16.1, p = 0.0024; AUC = 0.78, 95%CI:0.53-0.82) and at complete follow-up time (HR:2.67, 95%CI:1.04-6.8, p = 0.041; AUC:0.68, 95%CI:0.52-0.82).

CONCLUSIONS: We validated MiROvaR performance in identifying at diagnosis eEOC patients’ at higher risk of early relapse thus enabling selection of the most effective therapeutic approach.

PMID:34922264 | DOI:10.1016/j.ejca.2021.11.003

Mult Scler Relat Disord. 2021 Dec 3;57:103440. doi: 10.1016/j.msard.2021.103440. Online ahead of print.

ABSTRACT

OBJECTIVE: To evaluate the relationships among patient-reported balance confidence and social satisfaction and social participation in people with multiple sclerosis (pwMS).

METHODS: 75 ambulatory pwMS who had sustained at least two falls or near falls in the prior two months self-reported their balance confidence (Activities-specific Balance Confidence (ABC) questionnaire) and social satisfaction and participation (Patient Reported Outcomes Measurement Information System (PROMIS) measures). Correlations between the ABC and PROMIS measures were examined using Spearman’s rank correlation.

RESULTS: In a cross-sectional analysis, ABC scores and PROMIS scores for social satisfaction and social participation were statistically significantly correlated (ρ 0.37-0.54, p ≤ 0.001). The correlation between balance confidence and social satisfaction was consistently stronger at each time point than between balance confidence and social participation.

CONCLUSION: Self-reported balance confidence is associated with both social satisfaction and social participation in pwMS who fall. The causal direction of this relationship remains uncertain.

PMID:34922250 | DOI:10.1016/j.msard.2021.103440

Musculoskelet Sci Pract. 2021 Dec 10;57:102492. doi: 10.1016/j.msksp.2021.102492. Online ahead of print.

ABSTRACT

BACKGROUND: The pathophysiology of concussion is complex. Altered sensorimotor function post-concussion may contribute to the wide range of symptoms and impairments reported. There is currently limited evidence documenting changes in sensorimotor function during the recovery period. The aim of this study was to investigate the effect of concussion on the sensorimotor system in adolescents post-concussion using a multifaceted approach.

STUDY DESIGN: Prospective nested case-control study.

METHODS: A total of 285 male adolescent rugby players underwent assessment of sensorimotor function during preseason. Players who sustained a concussion during the season and control players, matched for age and playing position, were assessed in the subacute period (3-5 days) and after return-to-sport (3 weeks). Tests of sensorimotor function included balance, cervical spine and vestibulo-ocular function, and measurement of the size and contraction of lumbopelvic muscles (ultrasound imaging).

RESULTS: Twenty-three players (8%) sustained a concussion. Of these, 20 players were assessed during the subacute period and 17 players following return-to-sport. The prevalence of vestibulo-ocular dysfunction increased from 38.9% to 72.2% during the subacute period and dysfunction was present in 83.3% of players after return-to-sport (p = 0.01). Changes in lumbar multifidus muscle size (p = 0.002) and thickness (p = 0.05) at the L5 vertebral level were observed. No statistically significant changes in balance, cervical spine proprioception, or contraction of lumbopelvic muscles were found (p > 0.05).

CONCLUSION: Changes in sensorimotor function were observed in the subacute period post-concussion, with some persisting after return-to-sport. Using symptom-based criteria for return-to-sport may not adequately reflect the sequelae of concussion on the sensorimotor system.

PMID:34922255 | DOI:10.1016/j.msksp.2021.102492