Fine-tuning the thermal conductivity of amorphous silicon used in technologies such as solar cells and image sensors should become much easier thanks to the computational topology and machine-learning-assisted discovery of the relationship between nano-scale structures and physical properties.
Tag: statistics
J Comput Assist Tomogr. 2022 Jun 28. doi: 10.1097/RCT.0000000000001352. Online ahead of print.
ABSTRACT
AIM: The aim of the study was to investigate the diagnostic value of radiomics models based on computed tomography (CT) in distinguishing between benign and malignant thyroid nodules.
MATERIALS AND METHODS: We conducted a retrospective analysis of the clinical and imaging data of 172 patients with pathology-confirmed thyroid nodules (83 benign nodules and 89 malignant nodules). All patients underwent a plain CT scan + arterial and venous contrast enhancement before the operation. Using the stratified random sampling method, patients were divided into a training group (121 cases) and a test group (51 cases) at a ratio of 7:3. A.K. software was used to extract radiomics features from the preoperative CT images, and minimum redundancy maximum relevance and least absolute shrinkage and selection operator regression analyses were then used for feature screening and model construction. Receiver operating characteristic (ROC) curves were constructed for the training and test groups to verify model performance and evaluate the efficacy of the radiomics features in identifying benign and malignant thyroid nodules. We then used the most efficient models to construct a nomogram. For the training group, 1-way analysis of variance and multivariate logistic regression analysis were used to screen statistically significant clinical features, and the radiomics scores were combined to construct a radiomics nomogram. We used ROC curve analysis to evaluate the predictive performance of the model.
RESULTS: Screening yielded 21 radiomics features that were used to construct a model for differentiating between benign and malignant thyroid nodules. For the training group, the area under the ROC curve of the prediction models for the noncontrast, arterial phase, and venous phase scans were 0.86 (95% confidence interval [CI], 0.79-0.92), 0.89 (95% CI, 0.83-0.95), and 0.88 (95% CI, 0.82-0.94), respectively, and the corresponding diagnostic accuracy was 0.78, 0.84, and 0.83. For the test group, the corresponding 3-phase under the ROC curves for the test group were 0.76 (95% CI, 0.63-0.90), 0.78 (95% CI, 0.65-0.91), and 0.76 (95% CI, 0.62-0.90), and the corresponding accuracy was 0.63, 0.77, and 0.75. Thus, the arterial phase model exhibited the best diagnostic performance. The multivariate logistic regression results showed that morphology regularity and the cystic degeneration ratio were independent clinical risk factors for predicting benign and malignant thyroid nodules. The arterial phase radiomics score and clinically independent factors were then used to construct a nomogram. The nomogram had good discriminability for the training group (0.93; 95% CI, 0.88-0.98) and the test group (0.84; 95% CI, 0.73-0.95), achieving significantly higher accuracies than the radiomics score and clinical characteristics alone.
CONCLUSIONS: The radiomics nomogram constructed by combining radiomics characteristics and clinical risk factors was efficacious for distinguishing benign and malignant thyroid nodules.
PMID:35759774 | DOI:10.1097/RCT.0000000000001352
Rev Med Inst Mex Seguro Soc. 2022 May 2;60(3):268-274.
ABSTRACT
BACKGROUND: It has been pointed out that ghrelin and obestatin could have an impact on the genesis of obesity, since they estimulate and inhibit apetite and, therefore, food consumption.
OBJECTIVE: To compare the metabolic profile, lipid profile and the concentrations of ghrelin and obestatin in children with normal weight or obesity.
MATERIAL AND METHODS: Cross-sectional design with 97 normal weight or obese children, 6 to 18 years of age, who did not present systemic diseases. The serum concentrations of glucose, insulin, total cholesterol, triglycerides, high (HDL), low (LDL) and very low density (VLDL) lipoproteins, aspartate aminotransferase (AST), alanine aminotransferase (ALT), ghrelin and obestatin were determined. Descriptive statistics were performed. Student’s t test was used to compare groups, and correlation coefficients of ghrelin and obestatin values with biochemical and anthropometric variables. A p value of ≤ 0.05 was significant.
RESULTS: 55 children with normal weight and 42 with obesity were included; mean age was 10.7 years. Triglycerides, LDL, VLDL, ALT and insulin were higher, and HDL lower in obese children (p < 0.05). Ghrelin values were higher in normal weight children (p < 0.05), and there was no difference in obestatin values.
CONCLUSIONS: The lower concentration of ghrelin in obese children may indicate a negative feedback to regulate energy consumption. Children and adolescents with obesity show metabolic and lipid profile alterations that place them at risk of early development of cardiovascular risk factors.
PMID:35759751
Rev Med Inst Mex Seguro Soc. 2022 May 2;60(3):249-257.
ABSTRACT
BACKGROUND: The COVID-19 pandemic caused hospital reconversion throughout Mexico and it was scarce information about its development in second-level intensive care units (ICU).
OBJECTIVE: To determine the clinical characteristics related to COVID-19 mortality in a second-level ICU.
MATERIAL AND METHODS: Observational, cohort, retrospective, and analytical study. Demographic variables, medical history, as well as clinical, ventilatory and laboratory characteristics, and complications of patients admitted to ICU from March to November 2020 due to acute respiratory failure were recorded. Patients were divided into two groups: improvement or death. Lost data were imputed by normal multivariated regression. Descriptive statistics and inferencial analysis were made to determine the risk of significant variables against the death outcome with Cox regression.
RESULTS: 60% of patients were male. In-hospital mortality was 55%. An older age (44.4 ± 12.1 vs. 50.7 ± 12.1, p = 0.01), higher APACHE II score (8 (10-13) vs. 15 (11-21), p < 0.001), larger onset-symptom time to ICU (10.1 ± 4.0 vs. 12.0 ± 5.3 days, p = 0.049) and a lower oxygen saturation (78.2 ± 16.%5 vs. 71.1 ± 17.9%, p = 0.017) were significantly asociated characteristics to mortality. Average of stay at ICU was 8 days.
CONCLUSIONS: A higher age, more days from beginning of symptoms to hospital admission, and lower oxygenation at admission were pre-admission determining factors for risk of death, while cardiovascular, renal complications and hyperglycemia were the in-hospital determinants.
PMID:35759745
Anal Chem. 2022 Jun 27. doi: 10.1021/acs.analchem.2c00287. Online ahead of print.
ABSTRACT
Here, we develop a sensitive method for glucose-containing disaccharide analysis by 1-(4-carboxyphenyl)-3-methyl-5-pyrazolone (CPMP) derivatization using mass spectrometry. The intense anion of [M – H]– (m/z 759) was observed for CPMP-labeled disaccharides in a negative mode. After derivatization, its sensitivity was significantly increased with the limits of detection (LODs) and limits of quantification (LOQ) ranging from 3.90 to 8.67 ng L-1 and 12.99 to 28.92 ng L-1, respectively. During CID-MS/MS analysis, the fragment patterns of CPMP derivatized disaccharides in the negative mode were simpler and clearer than their counterparts in a positive mode, which further could be applied to distinct and relatively quantitative isomeric disaccharides with ultrahigh sensitivity and good reproducibility. The great linear relationships could be achieved under wider concentration ratios from 0.01 to 20 compared to the previous report. Eventually, the developed methodology was applicable to identify isomeric disaccharides in beers. No sucrose was discovered. All beers contain 1,4- and 1,6-linked disaccharides. Some of them also have a mixture of 1,2- and 1,3-linked disaccharides. Through the integration of statistical analysis, beers with different production processes were finally discriminated, and the relative quantification of isomaltose and maltose was realized. In general, this method is sensitive, fast, and reliable for the discrimination and relative quantification of isomeric disaccharides in complex matrices. This study provides a new idea for the structural analysis of oligosaccharides in food, plants, and animals and an important theoretical basis for the exploration of new functions of oligosaccharides.
PMID:35759693 | DOI:10.1021/acs.analchem.2c00287
Plast Reconstr Surg. 2022 Jun 28. doi: 10.1097/PRS.0000000000009434. Online ahead of print.
ABSTRACT
BACKGROUND: Intraoperative hemostasis should be performed with great caution since bleeding is a huge enemy of patient safety during surgery. Tranexamic acid (TXA) is a lysine synthetic derivate that inhibits fibrinolysis and diminishes the bleeding by blocking the 5 lysine-binding sites for plasminogen.
PURPOSE: We are comparing the efficacy of tranexamic acid vs. placebo as a hemostatic agent in liposculpture procedures.
METHODS DESIGN, SETTING AND PARTICIPANTS: We conducted a multicenter, double-blinded, randomized, controlled clinical trial in patients who were scheduled for liposculpture in 3 plastic surgery centers (Colombia and Mexico) between January 2019 and February of 2020. Interventions: 141 patients were randomly assigned into three groups: Intravenous (1 gr of TXA), subcutaneous (1 gr of TXA) and placebo (Normal Saline). 47 patients were assigned to each group. 30 patients were male and 111 were female. Main outcome: Evaluate the amount of postoperative bleeding between groups. The primary outcome was measured by the hemoglobin (Hb) point loss at day 1 (Preoperative Hb minus Hb at day 1 postop) and the Hb (mg/dl) point loss at day 5 (Preoperative Hb minus Hb at day 5 postop).
RESULTS: We found the Intravenous intervention group to have a greater hemoglobin level than the other two groups on both the first postoperative day (P=0.0001) and the fifth postoperative day (P=0.001). There were no statistical differences in Hb values between the placebo and the subcutaneous intervention groups.
CONCLUSIONS: Intravenous Tranexamic acid is a good therapeutic choice to implement on liposculpture procedures to decrease postoperative bleeding.
PMID:35759637 | DOI:10.1097/PRS.0000000000009434
Proc Natl Acad Sci U S A. 2022 Jul 5;119(27):e2119015119. doi: 10.1073/pnas.2119015119. Epub 2022 Jun 27.
ABSTRACT
Controlled electrobreakdown of graphene is important for the fabrication of stable nanometer-size tunnel gaps, large-scale graphene quantum dots, and nanoscale resistive switches, etc. However, owing to the complex thermal, electronic, and electrochemical processes at the nanoscale that dictate the rupture of graphene, it is difficult to generate conclusions from individual devices. We describe here a way to explore the statistical signature of the graphene electrobreakdown process. Such analysis tells us that feedback-controlled electrobreakdown of graphene in the air first shows signs of joule heating-induced cleaning followed by rupturing of the graphene lattice that is manifested by the lowering of its conductance. We show that when the conductance of the graphene becomes smaller than around 0.1 G0, the effective graphene notch width starts to decrease exponentially slower with time. Further, we show how this signature gets modified as we change the environment and or the substrate. Using statistical analysis, we show that the electrobreakdown under a high vacuum could lead to substrate modification and resistive-switching behavior, without the application of any electroforming voltage. This is attributed to the formation of a semiconducting filament that makes a Schottky barrier with the graphene. We also provide here the statistically extracted Schottky barrier threshold voltages for various substrate studies. Such analysis not only gives a better understanding of the electrobreakdown of graphene but also can serve as a tool in the future for single-molecule diagnostics.
PMID:35759664 | DOI:10.1073/pnas.2119015119
J Homosex. 2022 Jun 27:1-17. doi: 10.1080/00918369.2022.2087480. Online ahead of print.
ABSTRACT
Since the lesbian, gay, bisexual, transgender, and intersex (LGBTI) community may be exposed to violence, discrimination, stigma, exclusion, and maltreatment due to their sexual orientation while accessing healthcare services, understanding, and improving the attitudes of future’s health care professionals toward LGBTI individuals seem essential. This descriptive and cross-sectional study aimed to investigate the homophobia among medical, nursing, pharmacy, and healthcare sciences students and examine the related factors. The study included 2,531 students from medicine, nursing, pharmacy, and other health sciences (midwifery, nutrition and dietetics, physiotherapy, management of healthcare facilities) disciplines. Homophobia was measured with the Hudson and Ricketts Homophobia Scale. After getting ethical and institutional approvals, data were collected and analyzed using descriptive and inferential statistical tests. Medical students had the lowest homophobia score, and their mean score was significantly lower than other students. There was a significant difference between students’ scores according to years of study, age, sex, acquaintance with LGBTI individuals, providing healthcare services to an LGBTI person, and opinions on providing care. Although homophobia scores of nursing, pharmacy, and other health sciences students were lower than the medical students’, policies and expansive content regarding LGBTI should be in place in all health science educational institutes, including medical schools, to prevent students from holding homophobic and prejudicial attitudes against LGBTI individuals.
PMID:35759634 | DOI:10.1080/00918369.2022.2087480
Plast Reconstr Surg. 2022 Jun 28. doi: 10.1097/PRS.0000000000009466. Online ahead of print.
ABSTRACT
BACKGROUND: Scars are a vexing sequela of surgery. Microneedling, also known as Minimally Invasive Percutaneous Collagen Induction (MIPCI), has demonstrated impressive improvements in chronic acne scars; however, no evidence exists for treating post-surgical scars during active wound healing. The purpose of this study was to demonstrate the utility and safe use of MIPCI in acute post-surgical scars.
METHODS: Twenty-five subjects who underwent surgery had scars treated with 3 treatments of MIPCI in the postoperative period. Scar assessment was measured by Vancouver Scar Scale (VSS), Patient & Observer Scar Assessment Scale (POSAS) and Global Aesthetic Improvement Scale (GAIS) after each of the 3 treatments and at final 2 month follow up.
RESULTS: Patients had positive improvement in VSS, POSAS and GAIS at 16-week post treatment initiation evaluation compared to initial measurement (p value<0.001). No statistically significant differences were noted when comparing the age of the patient, location of scars or Fitzpatrick Phototype Scales between patients. However, when comparing patients who began treatment early (week 6 to 7 post-op) to those who began treatment late (week 13 to 16 postop), there was a statistically significant difference in the POSAS group (p value <0.04).
CONCLUSIONS: Post-surgical scars treated with MIPCI in the maturation and remodeling phase had no adverse outcomes. Interestingly, our data shows treatment initiated early in the maturation phase (6-7 weeks post-op) while natural collagen formation was tapering off demonstrated improved aesthetic outcomes compared to treatments initiated late in the maturation phase (13-16wk post-op).
PMID:35759632 | DOI:10.1097/PRS.0000000000009466
J Healthc Qual. 2022 Jul-Aug 01;44(4):240-252. doi: 10.1097/JHQ.0000000000000327.
ABSTRACT
Interventions to improve medication nonadherence in transplantation have recently moved from a focus on motivation and intention, to a focus on person-level quality improvement strategies. These strategies link adherence to established daily routines, environmental cues, and supportive people. The objective of this evaluation was to estimate the cost of implementation and the cost-effectiveness of a person-level intervention shown to increase medication adherence. To estimate the intervention costs, a direct measure microcosting approach was used after key informant interviews with project champions and a review of implementation expenditures. Cost-effectiveness was calculated by comparing the incremental implementation costs and healthcare costs associated with nonadherence to the incremental percent adherent, defined as the percent of patients who took greater or equal to 85% of their medication doses, for each pairwise comparison. The intervention was low-resource to implement, costing approximately $520 to implement per patient, and was associated with significant improvements in medication adherence. These implementation costs were more than outweighed by the expected healthcare savings associated with improvements in adherence. This person-level intervention is a low-cost, efficacious intervention associated with significant statistical and clinical improvements in medication adherence in adult kidney transplant recipients.
PMID:35759613 | DOI:10.1097/JHQ.0000000000000327